Heya Always nice to see a person who plays on the same server. If you need a hand just look me up My character's name is Aurora Avalon.
FC I'm in is very social and we're always helpful. Pretty sure I can get one of the officers to invite you

For Dragoon your second class requirement is Marauder. AskaRay already explained a good way to level that class. I would like to add one more thing to the list. Once your character becomes a Dragoon you can also use skills from the Pugilist class. And they have some very useful skills that you can make use of. And since Pugilist starts out in Ul'dah. You can level that one up very similar to Marauder