Roleplaying is just where you pretend to be an Idol, Ulzzang, or Actor/Actress. (Depends whats available)
You can talk to people and just have fun.
FB based RP's are quite popular but you can find some Rps that are on Tumblr, Instagram, or AFF.
The whole point of a RP is to talk to people, different RPs have different themes.
I recommend "Banana RP" (I'm in it)