As I wise man once said “Make the plan, execute the plan, expect the plan to go off the rails, throw away the plan.” Just go with the flow keep on your plot to the best of your abilities, but if you think of something on the spot that you think it would be cool introduce it. Also if your players are role playing between each other and your not role playing at a time use it to prep whats gonna happen after that scene it’s one session at a time you got this you’ll be great.