How should I start writing?

I always think that I like writing. I also think that I can write well. In fact, that is only what I wish. When I try to write, I really don't know what words I should write to start it. It makes me depressed. Then, I have different opinion of writing. "It's the most difficult job for me" I will never be able to do it. Now, I just write what I feel and what I think. Hopefully, someday I can write more words and better sentences. Writing needs great idea. That's why I will not be able to write well if I don't have any idea. Friends, whoever you are if you have the same experience like me and you have found the solution, please tell me.