Almost level 20, exactly how do I party? Stand in the central hub of Ul'Dah...and do what? I know theres no seek feature yet, but what do I do? I shout to join a group? That's fine, but I don't know HOW to party. What do parties do for xp? >>;
First of all, the fact that there is no seek feature is a misnomer. It is true that it is incredibly clunky and few enough people know about it to make it really useful, but it does exist. Going under Party -> Recruit, then selecting Seek Invite under the Purpose dropdown will make it so that anyone who uses the Party -> Search function looking for Seek Invite for your current class (at the time of starting the search) will see you.
As for partying, there are a few ways to go about it. At rank 20, I've found just finding a single friend and killing squishy critters around 10 levels above you to be the best experience, although others may disagree with me. Once you hit 25, you can get into a group running through the Toto-Rak dungeon which gives serviceable experience as well.