Is it wrong to ask lots of questions, and not really answer any? I try to answer as many questions as possible to "give back", but I find I don't know much. I always choose the correct answer and upvote good answers.
Nope, not wrong at all!
As long as you indeed choose a correct answer and up-vote the good answers, there's no problem in asking a lot of questions.
Especially if they are genuine questions which you actually want to know the answer for. Some people just ask questions for the rep, even if they already know the answer. And that in itself even isn't wrong if the question doesn't exist yet, and can be of use for future visitors. It's only wrong when they are blatant dupes, or just silly questions.
Good questions are the driving force behind SO system.
SO accumulates and organized its members' knowledge around the questions.
A good question is like a small seed planted in fertile soil: it will grow up to be a very good answer and assist to many other people.
So, go ahead and continue asking! You help SO grow!