I'm getting tired of hearing about the age issues. I don't want to be seeing posts about how young people are. I'd rather judge you by behavior and knowledge. I wouldn't care if you were 12 or 21. If you know what you're doing I'd let you turn wrenches on my rigs. I know some 21 year olds I wouldn't let touch them.
I never understood why kids write in to magazines and start with, "I'm 15 and got my first....". You never see anyone write "I'm 22 and got my first....."
Research the web, tech library, forums etc. Read Chiltons or Haynes manuals to learn the way and ask intelligent questions when you can't find the answers. People will respect you if you seem like you know what you're doing and show some examples of the things you've been doing and that you're not just a web wheeler. I can't guarantee you that everyone on-line will take you serious if you keep pointing out that your 13.
A lot of people aren't going to know you from reading all your posts. There may only be a few here who are actually familiar with your posts.
Some may only be seeing you right now as some kid who continues to mention he's 13 and wants to know if he should leave TRS because it's popped up in a couple of different topics.......