You're 13... and he's 18... he'd have to wait 5 years before you could legally be his girlfriend.
You can't expect him to break the law for you and date you now... and I doubt he would wait 5 years for you.
So, this crush won't become anything more than a crush... try to see him less... and hang out with your friends more.
"The weakest soul, knowing its own weakness, and believing this truth that strength can only be developed by effort and practice, will, thus believing, at once begin to exert itself, and, adding effort to effort, patience to patience, and strength to strength, will never cease to develop, and will at last grow divinely strong."
- James Allen