Depending on your zone their should be a starter island or two. After you complete those, the first zones should be on-level. Work your way through the zone without jumping too far ahead. Following the roads through unmarked areas should give a quest or two. Or if you have done all that, just try teaming up with some others to complete your goal.
^ what he said. Even if you skipped the starter island, go back and do it at level 8. You won't get as much XP but you should get a boost enough to get you back on track. Make sure you are doing the main quest at level 5 and the mages guild and fighters guilds quests as well. They scale to your level so they should be some good XP as well.
What covenant are you? One of the first things I did was explore the nearest cave/exploration area (Ilessan Tower for me as I'm Daggerfall) and fighting everything in there wasn't too ridiculously hard and helped me to level up a bit.
If not, then just run around and kill things for a bit I think!