If you want to learn Tai Chi you need to have a teacher, hopefully a good one. You can't simply copy the movements from a video or read about the principles in a book and expect to gain any skill whatsoever.
Once you have found a teacher however, you need to practice what you've been shown on your own and this is the only way to learn Tai Chi.
Through regular solo practice you learn how to teach yourself. Students who go to classes regularly but don't practice on their own make little real progress. This is because real Tai Chi is a very difficult art to understand. You can only penetrate it's mystery on your own.
When you practice on your own you are learning how to feel what's going on in your body. In Tai Chi we want to move the whole body together as one, how can you learn to do that? Well, go and find out in your own time.
Although regular time with a good teacher is vital, you may find that more and more you are able to answer your own questions. If you are enthusiastic about Tai Chi it's fun to talk about and I used to take every oppurtunity to bombard my teacher with questions. I think it's good to have an enquiring mind and I could happily chat all night to my teacher or anyone else who has wisdom to impart. These days I ask less questions and practice more. I feel confident enough to figure things out on my own. If I have a question about some aspect of Tai Chi I'd rather see if I can work it out myself. If I do ask about something it's often to check that what I've discovered is correct.
Too many questions and too much talk about Tai Chi can actually impair your ability to listen. As your mind becomes quieter, your intuition gets stronger and the solutions come to you unhindered. That happens in two ways, firstly you discover things yourself and secondly you are more open and receptive to advice.
As a teacher I am aware of how difficult it is to communicate the principles verbally. It's all very well telling someone to relax, to sink the weight into the legs and the move the whole body, they need to find out how to do that themselves.
Even when a highly skilled teacher physically corrects you, it's still you that's doing the feeling and the learning yourself. You could be training with Chen Xiaowang every week and unless you're making an effort to understand what's happening in your own body it would be a waste of time.
So in summary, whatever your reasons for doing Tai Chi.... go and practice and learn how to teach yourself!