Friendships start when people notice that they have things in common -- ideas, experiences, hobbies, interests, or other friends AND they expect to interact with one another regularly. Thus, you'll need an opportunity to share similarities and develop interpersonal trust through regular contact. That can be via classes, friendship groups, clubs or organizations you both belong to, etc.
The best chance of doing so is if you have a mutual friend who can include you in the friend group that he hangs out in. You'll have a chance to talk with him and then see if you share common ideas, a sense of humor, interests, etc.
Be genuine, but befriend a friend of his and you'll find yourself included in the group eventually. If that is absolutely not possible, join a club he's in, take a class he's in or learn about a hobby he's interested in (as long as you're genuinely interested). Start to sit near him if you're already in a class he's in, attend his games if he's in sports (especially if you have other friends on the team who can introduce you?), etc. Show some interest so you'll have something specific to talk to him about. (People love talking about themselves.)
When I was a teenager, a guy who was crushing on me decided to become best friends with my next door neighbor to get closer to me. They played basketball for hours on my family's basketball hoop. Sometimes I'd go out and talk to him. We ended up dating long-term.