Welcome to the forum. I agree with Walter in that many people who bought fly tying kid were generally not that happy about it.
I do not want to repeat what Walter mentioned above, but I would like to add a piece of advice about beginning to tying your own fly.
Think about what kinds of flies you want to tie first and try to get material. And think about the flies that are really effective in your river. Are those flies egg pattern or nymphs or dry flies or streamer? For example, I have been using wollybuggers, whose material are not that expensive and highly effective for catching bass here. Another fly that I love is pheasant tail nymph whose material are not that expensive compared to dry fly materials.
So, find out the flies you are going to use a lot and buy material and go for it.
Another advise is that do not try to be a perfectionist.
I still have flies that I tied when I began to tie flies. Some of them do not look like anything in the world. I meant to make a popper fly but it ended up looking a plastic foam tangled with deer hairs. But I caught some fish with it. Mostly bass.
Another advise is that when you find yourself attempting to use roadkill squirrel or rabbit, that is the moment when you need to have some interventions from people around you. In another words, fly tying can be really consuming, so be careful. Your family first and fly fishing later.