For starting out, I would start with simple things. Meditating with a candle, writing petitions, creating sachets, jar spells. You gather tools as you need them for whatever project you are working on. No need to collect a bunch of stuff you may or may not ever need. Everyone is different.

Also, witches don't generally believe in the devil (There are Christian witches who would, I imagine, and some Satanic witches do, though some Satanic witches actually don't. Most of us are Pagan and we've got our fair share of atheists and no devil there.), so you're coming here and asking us how to send a spirit back to a devil we don't believe it came from in the first place is awkward. But you can do a banishing. And there are articles about that too.

As for your specific symbol, it isn't one that is common in witchcraft. It's not to say that it isn't a spirit's sigil, though they are usually more complicated. It isn't related to any alchemical, planetary or elemental energies that I'm aware of. I am not in the business of binding spirits, so I can't say much more than that. There are hundreds of thousands of spirits with established sigils. There are lots of old grimoires with sigils in them. Goetia deals with demons and djinn and Enochian is angels, I think. sacred-texts.com might have a grimoire with binding sigils in it.

Another item you may choose is a crystal prism that hangs from the ceiling. These cause delightful dancing rainbows and breaks up stagnant and negative energy in the house.

As for asking any spirits for help with spells. The whole point of a spell is to overcome the material part of ourselves that interfere with the direct connection to the energy of the Universe. Spirits, including the dead, are made of energy. They don't need witchcraft.

For the general protection of a pet, many people use a charm on their collar. Both pentagrams and St Francis medals are popular.

As for the pregnancy, moonstone is a wonderful stone to use for pregnancy and onyx eases pain and panic and gives strength during childbirth and bloodstone encourages healing afterward. Nutritional support is also very important. I am usually dealing with veggi-eaters, so oat straw and nettles are my go-tos, but for an obligate carnivore, I am thinking oily fish and a bit of liver now and again, though cats tend to be picky.

Connor

Black magick is generally defined as magick that causes harm, either by its effects or via the methods and materials used. Blood magick would only meet this definition if it was used to harm someone or if the blood was taken from an unwilling donor. Most blood magick applications require your own blood, but not all. Anyone else's you use should know what you're up to and be fully on board.

With regard to dangers; You'll want to take the usual precautions against infection, of course. Bloodletting itself can be addictive and that can cause problems as well. Also, when using blood to feed a spirit or spell object, well, there's the theoretical risk that you'll end up needing to feed more than is good for you or that the spirit can use the blood to gain power over you. Likewise, if you are doing blood magick with another person you could be allowing them control over you by giving them access to your most powerful taglock.

Wait. I thought all species within a same family and genus had the same magickal planetary/elemental rulers. That's how Scott Cunningham's magickal herbs book explained it. He list white clover and read clover (2 different species) all under (Trifolium spp.) with the same magickal rulers and powers?

It can often be difficult to know exactly what species of herb a spell calls for as the person writing it down is probably just using what grows nearby and unless you know where they live, you can't always know what that is. So, you must make do with what you have and perhaps experiment a little. But magic-users do not classify plants the same way botanists do. Botanists describe plants according to their reproductive strategies- the shape of their flowers, fruits, etc. but magic-users describe plants according to their energies, and describe these by way of planetary and elemental correspondences. If you can discern what the purpose of the plant is in a spell and attune yourself to that energy, you may be able to find a replacement plant that nearly matches that energy and it may be a closely related species, or it might not. You can begin your search by determining the planetary energy of the plant and looking among other plants with similar energies. Of course, there's always the possibility that there is simply no substitute.

So, the answer to your question is this. Sometimes it matters. Sometimes it doesn't. If the different species have similar histories, qualities, growing habits, toxicities, fragrance, then you should have no trouble using the readily available species over the harder to get one. If you have no idea which species is required, you have to figure out the purpose of the plant in the spell and go from there.

The example of yew; the common yew has an incredibly rich and detailed history. It has thousands of years of Western tradition behind it and that makes it more suited to European-based magic associated with the dead than the Pacific yew. It may be that the Pacific yew also has thousands of years of tradition behind it, but it would be different Native American tradition and I would want to know more about it before I used it. The common yew is also more toxic and long-lived, which further associates it with death and rebirth. You could probably use the Pacific yew for some things, especially considering it is a safer, less toxic (but not non-toxic) alternative, but I am not sure I'd trust it to trap a soul. However, if you decide it's going to work, it's going to work better than it would if you're not sure.

Regarding birch- For wood, I would say most species of birch can be used for most purposes. They are, for the most part, quick-growing pioneer species that form colonies. Paper birch is often called upon for its bark, but other birches bark has similar properties with darker color, so you just have to use an ink that'll show up. However, I must point out that removing the bark damages the tree though bark that has fallen away naturally can be found. When burning for incense or creating oils, some species (subspecies Betulenta) are preferred due to their higher concentration of fragrant resins. (I am personally not a fan of the scent, but each their own.)

Alder is an interesting one because the common name alder is sort of all over the place. Can these other common-named alders that aren't actually Alnus spp be used in place of alder? I don't know. I would have to get to know the plants involved and I do not. As for the various species within Alnus/, I am sure some of them can. I wouldn't use a shrub in place of a tree or an upland species in place of a water-loving species, but all other things being equal, I'd go for it.

A few years back, I had a neighbour living in a flat right below mine with whom I became good friend (long story, but she viewed me as a big sister as I helped her quite a lot, she was just out of care and was having a very rough time…)
Anyhow, few years down the line, she became a 'born again christian' as she started going out with this evangelical preacher (who did not seem to like me much….)
At some point, they went off on holidays and organised (without my knowing) for the rest of the congregation to perform and exorcism of/in their flat - it was in the middle of winter and I could hear some weird noises which slowly became louder and turned into proper incantations and speaking in tongues or whatever. It was rather spooky, especially at the beginning as I thought the building was empty and I could not locate where the noise / mumbling / praying then screaming came from…
Anyhow, ever since (my neighbour moved out within a week of coming back from her holidays), I feel like they sent whatever problem they had to me, or that I have somehow 'swallowed it' and I've been like bound to this place / flat, going from really really really difficult work/life/family situation to even harder ones… I have tried - repeatedly - the usual salt, incense, sage burning, space clearing etc… everything I can think of and more but instead of getting better, I'm having huge difficulties and problems seem getting worse.

I can't write a novel here, but just to say that my friends even sometimes say 'we don't know anyone who is as unlucky as you'…. it's just weird, I am not depressed or weak or easily influenced, and this has now been going on for ten years, so i am quite resilient, but I am getting a little tired.

My question is thus twofold:
Is it possible that whatever was binding my neighbours has now been sent over to me?
and if so, how can I get rid of this / send it back / destroy it etc..

I really hope someone has some tried and tested suggestions; thanks for reading and your help!

But more than anything, have confidence that your magic is going to work so well the first time that you will never have to repeat the spell again. Intentions are very powerful.

Some signs that may indicate a problem include a general sense that things are off, feeling like you're not yourself, thoughts and urges that are outside your normal character, obsessing over a person, place or object, feeling like you're being watched, catching a glimpse out of the corner of your eye, and nightmares. These signs will occur a lot if there's a problem, not just once in a while. Everyone experiences these sometimes and it doesn't necessarily mean it's a problem.

You should also note that these can also be signs of mental illness and I highly encourage anyone seeking spiritual treatment to also seek psychological treatment because even if your problem is spiritual in nature and not psychological, people experiencing any sort of chronic symptoms whether they be physical or spiritual, are at very high risk for developing psychological issues too.