Welcome!
Advice #1: Read through everything we've got here. You can probably skip the "Hardline" board since you're not dealing with union members, but everything else is of value for you.
Advice #2: Paperwork is great, but your main challenges will be scheduling and personality wrangling. Practice scheduling and working around conflicts. Think up a list of 10 friends or family members whose schedules you know well. Try and assemble a good schedule that would get all of them into the same place 3-4 times a week for 2 months.
As for personality wrangling, it just comes with practice. We have a lot of scenarios posted around here, but also consider all of the assorted crises that you and your friends have been through in the past few years, and problems that have arisen backstage. How would you deal with them from a stage manager's position?
Advice #3: Learn what French scenes are and use them to track your actors, both in terms of rehearsal and plotting backstage tracks.
Advice #4: Your designers and production team are just as crucial as the director in the "get to know" area. Make sure you've spoken with all of them before rehearsals start. Keep them in reach and make sure they know anything that happens with the show when they aren't there to observe.
Here's a great game that we played a few years back that will get you thinking about all the ways a single choice can affect the whole production. This also gets into contingency planning. For every item, cue and person that's added to a scene, you need to be considering any possible mishaps that could occur with that person or item, both backstage and onstage.