Well you gotta talk to people first, silly. Just saying hi doesn't work very well - it's hard to make conversation out of that, and people don't like having to do ALL the talking. x3 Try jumping in on a conversation. Give your opinions on the current topic answer questions, play around, have fun! Act like you're already friends with everybody, and everybody's already friends with you! People around here are actually pretty friendly - you just have to get out there and show them you wanna get to know them. :3
Answering questions is probably the easiest way to do that. People love having their questions answered, and a lot of the time they tend to look up to those who help them out, even if it seems like the simplest answer. I've made a lot of friends over the years just by trying to be as helpful and informative as I can.