I self taught and one mistake I did make was underestimating the wind. What I thought was perhaps a mild 3 mph breeze was probably actually a 5-6 mph so I would say to wait for a nice clear CALM day.

If you go this alone then I would also recommend untrimming your sim plane and then take off with it and re-trim it in flight because you're going to have to do that with your plane. You and your son can each untrim the sim for each other so the one flying is unaware of what correction to make until in the sim air.

I'd also practice take-offs and landings quite a bit with a few different planes and try to find one on the sim that resembles your plane. I've never tried it , but I wonder if it might be ok to have the other person trim the plane while one is flying it. I know for me to maiden a plane and then reach for certain trim buttons during flight is sometimes a handful (especially if it's a new and fast plane for me)

Make sure you have a HUGE area with NO obstacles.