If I understand your question correctly, leves are issued in the cities, talk to the guys in the Adventurers Guilds. You can pick up leves in any city and do them, there is no restriction, that's why I was highlighting the zones with cities. Leves come in two types, local leves which are for crafting and regional leves which are for combat and gathering. Some local and all regional leves require you to go out to the relevant camp, once there regional leves can be started by interacting with the atherite.

There are missions that can be obtained in camps, but these are all to do with the Grand Companies and your level is too low to be initiated into these (25 is your magic number IIRC).

I like Coerthas as well. I especially like the music that plays while you are in there. The most spectacular zone is Mor Dhona, it is not easy getting there but it is definitely worth the effort, you are going to want to be there when 'dark' weather is on. If you want to get there I think the easiest route is south from Dragonhead in Coerthas, the westwards road in Black Shroud is not nice and the north path from Bluefog is down right nasty (and this assumes you can get to Bluefog in the first place ).

If you want to get all the gates and stuff there is this guide (not my work). If I was you I would think long and hard before clicking on this link, I find doing your own exploration (at least at the start) is much more rewarding.