Congrats on your purchase.
I would treat it like a new grow room. Test all parameters for a few days >at the very least< before introducing plants.
IMO....You need a min/max recording thermometer set in there all day on a (typical) sunny, warm/hot day for your area to see where the temperatures top out in there. Without a doubt....it will be far warmer in there than it is outside.
You also have to consider that when you introduce containers/plants/water...your humidity is gonna spike...especially at night. It may even show itself without plants in there once the vents close (they are auto open/close, right?) just from the moisture coming up from the yard. Again...you will just have to monitor it and see what it does. In veg excess moisture may not be a huge issue...but in flower it's no good at all/has to be controlled.
But you're off to the races...that's for sure....