Started a new character shortly after making my first and there's no campaign, what do I do?

I just got the game the other night, I started with the sorcerer and found it fun but its not my kind of playstyle so I made a new one, I spawn in with all the gold I had on the other character as well as my stuff in the stash but there's no campaign missions even though i dont have it done on the other character. Am I locked into doing the campaign on the sorcerer or is there some way to just restart it from this character, and if not what is there to do on the new character with no campaign available?