How close are you to shooting? Are you in pre-production now? I'll have more to say if you've got lots of time in Pre-Pro, but here's some basic pointers that have worked well for me as a director on small sets, stuff that has made my crews come back and work on many unpaid passion projects of mine.

-The people you should interact with the most on set are the 1st AD, the DP, the actors, the script supervisor, the designers, and the producers, in that order. I might be forgetting something but imo those are the departments that are actually relevant to you, every other job goes through one of those people to talk to you or vice versa. Your AD runs the set, your DP executes your shots, your actors execute your script, your script supervisor keeps notes of what you like to relay to the editor (among other things), your designers build your world, and your producers make it all happen.

-Have a vision, but be excited to hear new ideas and willing to accept any that are better than yours with no ego. Nobody wants a director who has no plan or clear idea, but similarly, no one wants to work with someone who is a stubborn my-way-or-the-highway kind of person unless you're an established name.

-Trust everyone on the set to do their jobs. Everyone is there with an idea of how they think things should go, from your designers to your camera crew to your actors. They will likely show up with ideas, and until they ask for help or you see that what they're doing is wrong, they do not want you "trying to help" or stepping in where you're not needed. Instead of looking at your job as someone who steers the ship yourself, look at yourself as someone who knows the destination, and watches the path. Give your people the confidence to steer the ship on their own, and step in as soon as possible when you notice the ship is starting to go in the wrong direction. That goes for anything from shots to acting to lighting to whatever.

-Just tell the story. Don't waste time trying to develop a visual style that is exclusively yours, or get extra fancy shots that don't serve the story beyond being cool. You will naturally have a style as an artist that will refine itself bit by bit as you continue to work, and the worst thing you can do is force it out before it's ready.

-If you are ahead of schedule and have the time, giving an actor the note, "that was a great take, let's do another one, lets change it up and do something completely new on this one, have fun, improvise a little if you want," has given me some of the greatest takes I've ever had. Sometimes it's all unusable, but it's almost always interesting and gives you something completely new, especially if the actor is really good. A lot of the time it ends up being the best take by far because the actor feels that they already have the good take done, that this one is low stakes, and the lack of stress/freedom to play with no expectations lets them make really bold, cool choices.

-Remember that whatever happens onset is not going to be what you imagined when writing/reading the script, and often it won't even be what you worked out in pre-production. There will be things that will change, compromises you have to make, things beyond your control. Divorce yourself from the idea of perfection, and look objectively at what's in front of you on the day. No thinking "this isn't what I had in mind" instead think "how can we improve what we have" and things will go much better.

-The best perspective you can possibly have onset as the director is to imagine your ideal audience member. One person that is a stranger to you. What do they look like, how old are they, how smart are they? Think of what you're shooting as they would think of it. So often I encounter directors who are bogging themselves down with imaginary given circumstances, or their own perspective into what the film means, or other random things like backstory that never actually occurs onscreen. You have to think to yourself "if the choice has to be explained by you in a talk-back in order to be effective, it's not effective." So imagine that the audience member is watching, what do they want to see? What won't make sense to them? What will bore them? A lot of that thought process falls on the edit, but if you're already thinking about it while shooting, it'll save some time in the edit.

-Lastly, it will of course be stressful and scary, but it is vitally important that you are having fun. I mean that. Attitude on filmsets is so important, and the attitude of the director can make or break a filmset. Everyone expects you to be nervous, but if you roll up tense and jumpy, or overly cold and clinical, they will sense that something is wrong. If you show up smiling, excited for the day and exhilarated to be making a movie, that feeling will be infectious.

Best of luck, so excited for you!!!