New to DMing

Hello, so I am starting to DM for my friends. I am beginning with the starter set's module but don't know how to work with most of the things in there. I have only ever just played while someone else DMs so I am finding it hard to adjust to the other side of D&D. Also, I have no clue how to work with my friends' creative, if you will, imagination to derail the path that is set. If you guys have any tips for me that, that would be amazing.