Welcome to this wonderful baseball community, fellow mom!
I had the same dilemma last year when my son was starting high school. We are relatively new to the midwest, originally from NY, and we didn't know anyone. I chose a school based on their academic program because as much as we love baseball, academics is a priority. We were lucky because this school also seems to have a decent bb program, although I have heard some conflicting opinions over the last few weeks. I will judge for myself if he makes the team.
In regards to making the team, all I can say is if the kid is a talented ball player with a good attitude, he should make it. I don't know anyone at my son's school yet and even if I did, I can't see how that would matter. I wouldn't want my kid making the team because we knew someone. I want him to earn it. He's been working hard during the offseason and we can only hope that these coaches will find him to be a potential asset to their team. I've stopped stressing over it. It's not worth it. You can only do so much. Worse comes to worse, you can have him play on a select/travel high school team. I started looking into a few of them months ago in case my son doesn't make the hs team. I read some old postings on this website and evidently some people feel that playing on a travel team during the hs years is better in terms of competition level and exposure, so who knows, maybe that's the way to go.
I don't know how much you've looked around on this site, but there is great information to be found. There's an excellent list of suggestions for making a high school team and lots of words of wisdom from coaches, players and parents. Most important is for your son to want it and to be willing to work hard at it. I hope I was somewhat helpful.
Good luck to both of you!