How to start competitive programming? [closed]

Question

I have been practicing coding for a while, but the problem is that it takes me a lot of time to write a solution for the problems. I want to ask if competitive programming can help me in improving this.

If yes, then how should I start and from which web sites could I use (like TopCoder)? I obviously won't be able to solve very hard problems for now. What should I do?

If no, what else should I do?

I also have another problem that I want to learn coding but the thing is that I feel that I am not very good at it. What should I do? It's like bugging me from inside.

I know some people may not find this question informative but please at least allow me to get an answer.