Starting Class

So, I am absolutely loving my placement, but I've noticed one thing that really causes me anxiety when I'm there. I really enjoy teaching and I teach every chance that my co-op gives me, but I feel like I am terrible at starting the class. Once I get the class settled, everything is great and the kids stay focused, but getting them to start working is a task and a half. They like to wander around the room, talk to their friends, sit in other people's seats, and just plain talk. I really don't like the cheesy 1,2,3 eyes on me, or the clap if you can hear me because I'm with 7th and 8th graders, and I want to treat them like their age, but it's difficult to do that when they won't listen. They respond to the clapping and 1,2,3 eyes on me stuff because they've basically been trained to do it, however, I feel awkward using that.

So tomorrow, since our mentors will be at the PDS meeting, my co-op told me that she wanted me to run the classroom the whole day. I taught today, so I'm comfortable teaching the material for tomorrow because they will be working on the creative expressions lesson I have them doing for Ollie's class, but I'm super anxious about getting the classes started. I know the sub will be there if I need help, but I'm really trying to think of some different ways to start classes? I didn't realize I was so anxious about it until I took a nap today and had a dream about it! haha So, if any of you have suggestions for me, I'm all ears! Thanks!