How to talk to a guy?

I'm homeschooled and leaving for college soon so currently I don't get out much, but have online friends and there's this guy I like but I don't know how you could start a relationship through the Internet lol. I just want to know what I should do I don't really know him but you know I ”know” him because I follow him but I want to talk to him but I don't know how to start a conversation with someone that you half-know??