Most of the group rides I go on don't know what a paceline is. Somebody gets up front, sets a pace, others follow. While there is drafting involved, there is no rotation of the line.

OP, most important thing is to maintain an even pace in the line, do not yo-yo.

Watch the riders in front of you but don't stare at the wheel in front of you. Better to stay further away from the rider in front of you than risk running into her. You don't want your front wheel to get ahead of her back wheel.

I expect a slight decrease in speed when the group hits a hill and back off the rider in front of me or at least be looking to do so. Many groups fan out on a climb and the riders go at their own pace then regroup at the top. I once was too close to the rider in front of me when we hit a climb and he went back a bit. Our wheels touched and I went down, taking another rider with me. Got a nice bit of road rash for that.

Some groups expect you to say "STANDING" when standing up on the pedals. This is because many riders will "throw" their back wheel back a bit when they stand up. It's a nice courtesy but better to practice and not shift the bike at all when standing.

Again, most important to maintain an even pace. Anytime Mr. Slinky gets in a paceline, it gets tiresome and frustrating for the group behind him. Worse is when he doesn't take the hint as they ride off the front to get away from him and he insists on getting back in the front of the line. That's when the yelling and heated explanations start.