I'll be a DM for a group of my friends soonish for a play through of the D&D 5 starter set campaign. I've played with this group for a few months but some more experienced players have been taking over the role of DM. Since it is now my turn and I haven't done this before, my question is how much time should I invest in creating a story beforehand? How much detail should I put into storylines when preparing? I want the players to feel like they are in control of where the story goes, which likely means I will encounter situations I am unprepared for no matter what. How do some more experienced DMs deal with this? Are there any tips for a newbie to start this off on the right foot with my players? All advice is appreciated!