Crmoores has a good overview. But as you specifically said Riveria Maya, you are on the spot for calm beaches, young adult friendly, all inclusive properties. Likely in the area south of Puerto Morales to north of Playa del Carmen. You will find 3, 4, 5 stars to match. Various travel websites will sort based on stars and price. Travel agents and tour operators will help as well.

I do suggest that all inclusive may work for a group. No issues of transportation once onsite. Multiple restaurants, bars, and fun!