Level to 15 and follow your storyline quests. At a certain point retainers are unlocked as is the joining of a GC (mount riding prerequisite).

I think hunting log is just exp.

As for what order to level classes its up to you. Only thing I would suggest is when you get something to 30 then level the other class required to 15 and unlock the job. There are some cross class skills you will want but you can worry about that later.