Krokatopia is your next main world in the storyline, so do that first. Grizzlehiem is whats known a a side world. You don't have to do it. It's way to hard for you at that level anyway so I would wait to do it. Just do Krok and good luck!!
oh ok thank you for clarifying that for me. On my Death Wizard I ended up doing Krok and Marleybone before Grizzelheim and I noticed the xp was close to nothing. It made me not to want to do it at all. But now I know there is a purpose down the line. Thank you,
just thought I would let you know, krok is a world that's mandatory so you have to finish it In order to get to marleybone, mooshu, dragon spyre, etc. however, grizzelheim is just a side world with extra quests just for fun
since Kroktopia is a story lined world stick with that first Grizzleheim is a side world that will eventually get you to wintertusk which is unlocked at level 48. I advise you guys to stick with the story line till you defeat malistare in dragonspyre.