New to non-recreational swimming; What do I need to know?

Hello! Hopefully this is the right place to ask this. Obviously most of you are experienced and it's possible that newbies like myself aren't welcome but I haven't gotten that impression... Feel free to correct me. Anyway, I'm a young guy who's looking into joining my town's swim team. I've always had a lot of fun swimming in my free time when the opportunity arises, but only now have I considered doing something more. Before I sign up I feel that it's necessary for me to grasp at least a basic understanding of the fundamentals of competitive swimming. If anyone has some advice on where I should begin research then it would be greatly appreciated if you could share. Thanks much! PS- I'm 6'9" with most of my height in my legs and am curious what style these genetics could benefit most.