If by "packs" you mean group rides, and I'm assuming you do, there are a variety of ways to ride. By that I mean if it's a paceline there are rules that are different than just group riding recreationally. I would suggest asking for advice and descriptions of the rides. Hopefully you can find a seasoned rider who is willing to help you. I would also suggest starting out in a group one step lower than you are capable of riding. It may help you to learn the rules and techniques without the need to be on top of your game physically.