Start doing every quest you find, the game is now quest oriented, that means that you'll get WAY more exp by doing quests than by grinding.
The first CQ board is in Heiharf (or is it Heiharp, you get the point). Just do every quest you can, they give high exp, and at some quests lines, they give your argates.
The nearest dungeon that you'll get is crespo.. When you're lvl 60, you can start doing daily a quest in crespo, it'll give you 1m exp for killing Laiden in crespo C (it's free, but you can only do it every 24 hours).