Never worry about leaving areas. I think it is very seldom that you will finish all there is to do in an area the first time you visit it. Just move on when you don't know what else to do. Traveling to new areas helps make the game fun. You can always go back and revisit areas to finish things up. I think that it is about impossible to get yourself into a situation where you can no longer beat the game because you didn't do a certain task on time or did things out of order. Time doesn't matter, and order rarely matters except for needing to acquire certain items to do certain tasks.
But, if you go somewhere that is too difficult, leave and go back after leveling up a few times.
Just to give you a sense to where you are in the game.The Monestary, road to Arnika then the town of Arnika itself. This is about 15 percent of the game.
You've got a lot more to do and explore. There are at least 3 quests here that will require you to leave then return to Arnika to complete them.
Happy adventuring!!!
Spence