trust yourself more; no one is perfect and of course u have things they don't have. think this way "u deserve what u believe" if u believe that u deserve the best thing in life then u will get it; it's not that simple but u can give it a shot :)

Visualise yourself being confident, practice speaking & smiling in front of a mirror is very helpful. Think of a few topics that you will talk about, eg local news, issues etc.

I think this question should have been 'How to change my personality' because it's basically about your personality. More than anything else, you will have to be confident with yourself. Being conscious usually comes from your own thoughts like your something is lame or worthless so I don't think you frequently look into the people's eyes when you're with them. You should to heal it if you have any open wound in your heart. And don't let other's opinions discourage you, you will never have any friend if you're afraid to have an enemy.

it will be better when you are old enough.

hmm. i dont know how to help you w/ that? maybe just try to be open or be talkative, its one way of improving you're self. 1st try to talk a little then try it a little more. its just like practicing. hmm' sorry if i cant help u that much