I know exactly what it's like to start the new school year in a new school. Throughout the course of my career, I have been in 14 elementary schools in 6 school systems in 3 states...so far. It can be a time of high anxiety, for sure! Hopefully these little tidbits will help you be socially successful in your new assignment.
Don't go in acting like you know everything. That is definitely a turn-off. Even if you have something to say, sometimes it's better to just sit back and listen. You'll get your turn later...after people know you.
Your first meeting with the faculty can be a time of anxiety. I have found it's best to go in, find an empty chair, and ask if it's okay for you to sit there. Most of the time it will be okay, but it's very appropriate for you to ask.
Sit quietly during the faculty meeting. More than likely you will be introduced and asked to say something about yourself. The faculty doesn't want to hear your entire vitae...just where you graduated and a little something personal (married? kids?) is all they need/want. This may help you connect with a member, and they may approach you with a question or to let you know something you have in common.
Lunch time can be lonely. It took 5 years at my mountain school before someone invited me to lunch. 5 years, y'all! Of course, I'm not there every day & my room is away from everyone else, so I'm sure they just forgot about me or didn't realize I was there. It's okay to ask a group if you can join them for lunch.
Take a walk through the school and pop in on teachers. If you noticed something in the room, mention it to her/him; it will get the conversation going. Double bonus: you'll begin to get familiar with the building and where your students' rooms are. Make sure you don't overstay your welcome, though.
Last, but not least: Don't be afraid to ask questions. From procedures to how the copy machine works, no question is a stupid one.
I can't stress this enough: make friends with the office and custodial staffs. I take brownies to one of the head custodians every now and then. I started taking them right after he made sure my heat was fixed, then found out he has no one to bake for him.
Becoming part of the faculty will not only give you sense of belonging, but you will have the respect of your coworkers. That, in turn, will make so many things easier on you. Teachers will be more flexible when you need for them to be, and may even bend over backwards for you!
Do you have any other suggestions for a smooth transition to a new school?