I think this quote may be appropriate here:
"Life's a dance, you learn as you go. Sometimes you lead, sometimes you follow. Don't worry about what you don't know. Life's a dance, you learn as you go."-Country Song by someone I can't remember who
You're nervous trying to meet someone new, but it's okay. You will get better! Don't worry about what you don't know-you don't know how they will react to you, if they'll like you, etc. Just try to be yourself and talk to them. I know, easier said than done, but trust me, practice, and you will get better. I did and I have been getting better ever since.
Try to be yourself. If they don't like you as you, then they are not going to be a good friend to you.
Ask questions, but not too personal. Good ones might be about if they have siblings, do they like a certain type of hobby you like (although not something weird, something like sports, movies, books,etc.). I also wouldn't mention you like certian books right away b/c some can offend people or freak them out, ie. Harry Potter, LOTR, DaVinci Code, Brokeback Mountain. If you are at a Harry Potter event or something, ask their favorite character. Many questions you can ask without offending or making someone feel uncomfortable.
Take care of yourself. Shower, look presentable. People will be more apt to look at you and talk to you if you look like you respect yourself. It doesn't mean wear your prom dress/tux every day, but just don't look like you just rolled out of bed all the time. (It's okay for if you are sick or if you are just maybe hanging out with your closest friends, but meeting new people requires some kind of shower/presentable clothes (not jammies, unless a pajama party).
Don't talk about gross things like your period, sperm, sex stuff, etc., especially at the lunch table.
Don't interrupt or talk with your mouth full. Wipe your face when you eat. Make sure you know what time to meet your friends and wear a watch to keep track of the time. Carry a timer with you if you must so you won't be late.
It's okay to be fashionably late for certain kinds of parties, dances, etc. Ask when your other friends will be going before you decide when to go.
Make up an event calendar of where you will spend time with people and be sure to schedule some alone time too.
Make up a weekly lunch time with a friend or a special time to hang out. My friend likes to watch Law and Order: SVU and she has parties every Tuesday night when it comes on. We go to the parties, hang out, and watch the show. It's only for one hour and about 5 people come. I've gotten to know some cool girls since coming there this past month.
Make up a time to call old friends from high school/childhood each week. I need to get better at this. You can catch up on things you've missed in their lives. It's fun to reminisce on the "old days" too.
Schedule homework and social time appropriately. Don't spend too much time socializing or you won't get any work done! However, you do need to have some time for friends and fun! Balance is key. This is still something I'm figuring out.
Remember what Eleanor Roosevelt said: "No one can make you feel inferior without your consent."
It means that no one can make you feel bad unless you let them. If people try to put you down, then just ignore them. The people that try to make you feel inferior are not worth your time. Don't give them that consent to make you feel like you are less worth it than them.