with that number of people it shouldn't be too crazy.

A few things to remember:

always expect there to be people around you - so don't ever move laterally without looking even if you don't hear someone indicate "on your left"

If you are going to pass someone indicate that you are there, by saying "on your left" and don't ever pass on the right.

Don't join a paceline without asking, but don't worry either if you get stuck behind someone for a little while before you pass them. Just don't freak them out by following very close, while being entirely silent.

Always indicate if you are stopping or slowing, both with hand signals and vocally - it is also nice to point out road hazards - potholes and glass etc.

If you are slower up the hills, try to stay to the right so that others can go around.