meeting spot at rome termini station?

Why don't you meet him in front of your train's intended departure track?
It takes 10 maybe 15 minutes to walk from the main entrance to the tracks area at Roma Termini. I'd enter the station at around 8 AM

Thanks. I thought about that, but that just seemed too easy! Our son speaks Italian, we do not, so wasn't sure if we'd need his help navigating the train schedule/departure platforms.

I think im overthinking this

I met my son at Rome Termini a few months ago. We met at the end of platform where his train was arriving just outside the glass doors at the end of the platform. It worked well.

Our son speaks Italian, we do not, so wasn't sure if we'd need his
help navigating the train schedule/departure platforms.

You don't need to speak Italian to read the departure/arrivals board. Just know the terms and your train number and final destination.
Track usually not listed til about 10-15 min before boarding time

You might want to read up a bit on train travel in Italy here:
www.seat61.com/train-travel-in-italy.htm

If your son is usually prompt, I would just have him meet you in the lobby of your hotel. It would simplify your needs and drop any worries. I would be standing in the train station by 8:15am but adding much more time if you are doing this by yourself. Have the Trenitalia app on your phones.

thanks everyone. I really am just overthinking this. I always get nervous about missing trains/planes etc.

I will likely just let my son decide what he wants to do. he will have been in Rome for almost a month by that point, so he will likely be able to figure out what is best!