Xanthar's Guide to Everything Marketplace Purchase Question/Issue

I just recently purchased Xanthar's Guide to Everything.  It came with an adventure "Underworld Speculation".  I want to run this adventure with a couple of the guys from my current marketplace purchase of the "Sunless Citadel".   When I create a new game the Sunless Citadel comes up as the default game for this new session.  It looks like i can delete it but i am afraid that if i do so i will delete the progress we have made in the sunless citadel in my other game.  Can you run more than 1 marketplace purchased game at a time?

Every Game is completely separate.  Anything you do in one will have no effect at all on the other.  You can create as many games based on a purchased module as you like (or with purchased Addons, for that matter) and make any change you like and it will have no effect at all on the other games based on it.  You are good to do whatever you like in either game.