DR Platinum has always had a very small community.
DR Prime has... 452 players in there right now.. and usually 400-600 24/7.
DR is very newbie friendly, but don't expect to be led by the nose. You do what you want, when you want, wherever you want to. The help system is well done and there is an aid for novices to help them find locations and get their bearings. Better than that, though, is the Mentor system, which is comprised of volunteers who will help you get started and answer any questions for you.
IC is not required. OOC is completely discouraged. No one wants to hear about football, politics, or listen to leet speak, etc., in game.
Most everyone is very friendly and helpful.
I would suggest the 30 day prime trial over the 90 day plat trial, if you aren't already familiar with DR.