I'm level 18 now. Haven't done a ton in the main quest, have done a good chunk of the companions quest, mostly I wander around and do random quests, like one quest where I found a "beacon" that I had to bring back to this shrine and it ended up with me getting a ton of gold, an awesome new sword and some other random crap I could sell. Good stuff. Trying to focus on the main quest but I get distracted
