Yup, want my muffins to stay safe.
Check out some of the smaller charity rides before tackling something like Ride for Sight or the BAD Ride. It will give you a feel for larger groups without making you feel too hemmed in.
Also, be aware that most of these rides act like a slinky: slow and all bunched up, then stretched out and fast, then slow again. It gets tiring (and tiresome) and the slow portions can be painful on a sportbike.
The bike shows often have booths promoting charity rides, so check them out and don't be shy asking about their safety record and how they structure the ride. The good ones have smaller groups staggered, instead of one big free for all.