Again I can relate to this situation as well. To cut a long story short I never really tried to make friends in High School because they just didn't seem like the people I liked hanging out with. I had friends in classes, but that was about it.
Fast forward to Uni, and history is repeating itself. I only have guy friends and 1 girl I know who talks to me occaisonaly. There's another attractive girl as well but I haven't spoken to her.
Back to your problems though. You should probably try talking to as many different kinds of people as possible as a begginers step. It doesn't have to be anything philosophical, just mention how great the weather is/isn't to someone else and see if the conversation goes somewhere. If it doesn't - no problem, the more you practice talking the better you'll get like most other things in life.
Its easier said than done I know, but joining clubs or gyms near your home or school can help a lot as well. It'll probably help you to feel your doing something proactive, like you belong to something, and you never know - you'll probably meet people there that are like-minded and want to talk to them as well.