I would have suggested heading over to The Goalie Shop for some quick 1-on1s with them, but unfortunately they have closed their doors.
That's what we did with our 8 year old. We just wanted to see if he had any sort of skill for the position before we invested in him playing it full time.
I don't really know of anything else out there right now unfortunately.
You could check with
World Pro Goaltending and see if they have anything like that.
If you are going to send your kid to a summer camp you'll need his own gear, so you're somewhat committed at that point; unless you can find a set of equipment to use for a week that is.
For a summer camp, I highly suggest
Torjager Hockey.
They have 3 camps this year and all are being run by Jeff from The Goalie Shop. Jeff has been awesome with our son and is a great goalie coach.