The way you are going to go about making gay friends and finding other gay teens will depend somewhat on where you live. If you live in a large metropolitan area, it might be easier than if you are in a rural or suburban community.
But even if you don't live in a city, don't despair! A surprising number of smaller communities do provide services for GLBT youth. There are a number of ways to go about finding other gay teens in your area!
The organization Advocates For Youth runs an awesome GLBT youth website called Youth Resource. Just like the name implies, it is has some excellent resources for GLBT teens.
Make sure to check out their very comprehensive list of youth programs. All you have to do is type in your state.
You can also contact your closest GLBT community center and ask if they offer any teen or youth programs.