It really all depends. I do some rides that are officially "no drop", and they try to put you with a few people according to skill level. This is annoying, it usually just involves long times waiting on the sides of roads.
There's also some in my area, one called "Wednesday Worlds", that is an intentional-drop ride. You get dropped, and you go home.

My advice would be to choose a group ride that is geared for your level. Many rides are rated somethig like: slow, medium, fast, or race. That being said, I usually just try to ride with a group of friends, but if you think organized group rides would be fun, definitely go for it.