Just play them both to your leisure. If you don't like playing more than one game at a time just play one of them to your liking and then start playing the other when you either get done with it or bored with it.

One of the best things about the Elder Scrolls game is that it has alot of the same characteristics of online rpg's yet it doesn't have a monthly fee so you won't feel like you are wasting your money if you don't play it for awhile.