I want to learn to communicate effectively.
What are your reasons for wanting to bet better at communicating?
I want to be able to convince people about my ideas, so they can understand why I do what I do.
Effective communication is definitely an important skill. I applaud you for trying to better yourself by learning new skills.
I also want people to understand me so that it'll be harder for them to reject me.
I'm sorry to hear that people have been rejecting your ideas in the past, and I hope that better communication skills will help you to win their approval.  While it's good to present your ideas well, it is also vital to have good ideas to begin with, so while you are at, get a trusted friend to offer real critiques of your proposals.