Even if tavern roleplay isn't the most fascinating out there, it is the easiest to find. It may feel awkward or confusing to start roleplaying with a stranger, but chances are they're looking to roleplay with you as well. Just stroll up and emote (/e) that you're ordering a drink or something, and make a comment about something your character observes.

Roleplay may include many complex stories and interactions from time to time, but as a whole it's a pretty simple venture. It's your character talking and interacting with other characters in a way that makes sense. Just think, "What would my character do?"