I will admit that it is hard to start in someplace new. Everyone feels awkward in school whether they acknowledge that or not. My advice to you, as one shy person to another, is to smile and say "Hello" or "Hi" or some other type of greeting to several people you don't know every day. Get used to doing this. You will face this type of situation many times in your life.
Get on the school's website and see what kinds of clubs / extracurricular activities they have going on. If you see one that sparks your interest, go to the introductory meeting and scope it out. It will be easier to connect with someone that has the same interests as you.
You might want to stay invisible, but that will just make you lonelier. So, chin up, you've got this. Smile, greet people, and see what the school has to offer. Be positive - that's what people will feed off of. Check back in with us and let us know how you're doing or if you need more help.