
Hey there, and welcome aboard to Balmung and the RPC! 
So, I'd suggest hitting the main listings over here:
http://ffxiv-roleplayers.com/forumdisplay.php?fid=15
http://ffxiv-roleplayers.com/forumdisplay.php?fid=53
Beyond that? Hit the Quicksand Adventurer's Guild in Ul'dah. That's the best place you can go to try your hand at RP and get used to everything. It's the de-facto place for pick-up RP (otherwise referred to as random RP). You can also freely observe other RP'ers if you want to get a bit more used to it beforehand, because there is a TON around the Quicksand at all hours of the day and night.

So, I'd suggest hitting the main listings over here:
http://ffxiv-roleplayers.com/forumdisplay.php?fid=15
http://ffxiv-roleplayers.com/forumdisplay.php?fid=53
Beyond that? Hit the Quicksand Adventurer's Guild in Ul'dah. That's the best place you can go to try your hand at RP and get used to everything. It's the de-facto place for pick-up RP (otherwise referred to as random RP). You can also freely observe other RP'ers if you want to get a bit more used to it beforehand, because there is a TON around the Quicksand at all hours of the day and night.