Tumblr is a blogging site that is divided into two main factions. The hipster side and the fandom side.
The hipster side is riddled with your average hipster, blogging with pictures of nebulas with song lyrics, or posting pictures of "hipster" fasion.
The fandom side is however, the side you want to be on. It is filled with fangirls and fanboys, and people who never sleep. They'll be nice to you, and help you with depression if you ask for it. There are many roleplaying blogs and ask blogs here that have great admins.
Note: If you ever send hate to anybody on Tumblr they will viciously attack making you regret it. Everyone will try and find out who you are if you're on anon, and if they do find out who you are you will probably be bombarded by hate.