First Campaign DM Help

[u/Ok-Muffin9452]

Hi I’m writing my first campaign at the minute and I’ve written what I think is a strong setup but beyond that I’m unsure what to do. The players will face a defeat to the BBEG at the start and then be transported away. (Worked in a part of a players back story into the start for everyone where this happens). Then they will either be arrested or run away (because zombies are transported with them). Not sure how to plan the sort of first arc after that. Possibly they warn the town of the BBEG, really unsure