Witchipedia

No, you don't need to follow any one tradition. Like anything in this world, our natural tendency as humans is to categorize and label everything. We crave structure and patterns. Just like Christianity has several sects and branch-offs, so too does Paganism. There are those elitist types that will tell you that you need to read a certain book, or visit a coven in order to become a "witch", but the truth is no one has the answers. Only you can find that magick within yourself. Find what works for you, what calls to you, and see where it goes. I will say that there are some fundamentals that every magickal person should know (i.e. protection and grounding), but the rest is up to you. If to you, looking up at the moon and meditating is magickal, then do that. If you like a little more structure and ceremony to a ritual, then incorporate certain tools or symbols that you think with get those magickal juices flowing. In the end, it must be enjoyable and even a little fun. Don't do something you feel is tedious or overwhelming. Do what feels right. It's all good!

Witchcraft is folk magick. Period. The end. Our magical ancestors practiced what worked. If that meant Wassailing a tree, or reciting the Lord's prayer, or sprinkling graveyard dust. Techniques were passed down the generations, picked up from neighbors, adapted and passed down again. New techniques can be discovered through experimentation and adaptation of existing techniques. You don't need to pick one tradition or reject others. If it's interesting, experiment. If it works for you, keep it. If it doesn't, well, you've learned something and that is what it's all about.

If you do not want to dedicate yourself for one sole purpose or one sole way of doing magick, and you just want to do magick with what works and how you want to do it, screw finding a branch. I don't have a branch. I research what I wanna know and I make the best of it. Some people may solely get into witchcraft for the ways of the sea, but that ain't me. I like the sea, so I can do stuff that would be considered sea witchcraft, but that's not "what I do," it's not my whole craft. I make potions, I cook, I write, I make sigils, and it doesn't affect how well I can perform magick. I'm a great witch, and people know that. Most magick is connected in one way or the other. For me, I find it actually helps to not strictly do one form of magick because I'm constantly learning new things about how magick works, how I can use it, the way my OWN magick works, my mind, etc. I've made my own tradition and I have been just fine. Now, if you want to follow a specific branch, that's amazing. Power to you. You can learn as much as you want with that. If that's your passion, by all means make the most of it and screw anyone else you thinks you can't do what you like to do. It's your craft, not theirs. Practice magick the way YOU want to practice magick. If you think you need to work on one area of your craft for whatever reason, then work on that area. Develop and grow. You can make your own decisions on what's best for YOU.

Pick n'mix is fine. It's about what you feel comfortable with and empowered by. I would suggest a few fundamentals, such as herb usage and significance, and correspondences to give you a foundation of knowledge. Also, take note of the moon phases. Other than that, do what feels right. A spell can be convoluted with ceremony and tools, or as simple as a few words spoken hastily. It can even be in your head. That said, old spells have an energy of their own, so it's worth seeking some out, but it doesn't have to be from a particular tradition. For example, I have asked to join a traditional pre-Wicca pagan coven, their tradition is oral so they don't have a collective book of shadows. over the years they have introduced a few Wiccan elements, a bit of shamanism and whatever gives them energy. It's healthy to be eclectic and take the best of other traditions and wisdom. Alternatively, some people prefer to be purist about one particular path, but one is neither better nor worse than the other. My personal view is that embracing the wisdom of other cultures and traditions increases my personal learning. The Chinese, for example, are second to none in herbalism. I do, however, respect those who stick to one particular path as purism can have a spiritual advantage to the seeker.