Ok, a bit more of a serious reply.

There are a number of other good suggestions already. I like the one of staying at the back for your first group rides. Observe how they are riding. See what communications they give concerning upcoming stop signs, obstacles such as potholes and bumps. A club ride peloton ( not like in races) generally works together to help conserve energy so that the group can rider faster than a single rider. The group should be very smooth with gentle accelerations to avoid a yo-yo effect. And as a rider you should be very smooth as well and keep peddling most of the time. There is nothing more detrimental to the group than speed up/ slow down. This will cause riders to cross wheels and when that happens crashes can occur. I would say that most injuries from group rides are caused by crossed wheels. (overlapping wheels). Should you overlap let the person know you are in an unsafe position until you fall back a bit. ("I'm on your right".) ("Clear"). Communication is a great thing for safety. Now some club rides are not totally "hugs and kisses". Our club has a Tues night Hammerfest and this is still designed to be safe but at various points in the ride if you want to be Lance for the night well then have at it and go off the front. Other people will try to hang with you and may bust your butt as well. This, in our club, is kept as a fun friendly exercise and we all try to finish together. Ah... how does this relate to drafting. As you get stronger you will not which riders are also stronger. You want to draft these people who will not let a gap open up in the drafting peloton. It takes a lot of energy to close down a gap that has opened up in these types of rides. So when you ride with a new group ask what kind of ride this will be. Not good start learning drafting on a Hammerfest type night.
Good luck and enjoy group rides. They are fun.