Having friends with motorcycles and riding together is one of the most rewarding experience for a new motorcyclist. But keep in mind when riding in big groups, some of the benefits of safety are lost.
Being nimble and agile can be cumbersome and restricted when riding with other motorcyclists. Riding in formation or staggering yourselves within a lane will help give you guys enough space to address any hazard you guys may encounter while riding on the road together. Make sure you guys keep at least a two second space margin from the rider directly in front of you, and work out your destinations ahead of time.
Having a lead rider in the front, and having a sweep rider in the back of the group, who both know the destination, will help to keep everyone together and to maintain a safe and comfortable ride.
Big groups will never really have riders of different skill levels, focus on your own ride. If you're a new rider, almost guaranteed that the other riders in your group will be faster and more experienced than you. Don't try to keep up. If they're people worth riding with, they will wait for you at the next turn. Maintain your pace, stay with your group, don't ride beyond your limits, and of course, have fun.