Pitcher Dad - Welcome to the hsbaseballweb!
Your situation is not uncommon. Our older son who went on to play 4 years at a D1 power and is now in the minor leagues had a very similar one.
But first, I was amazed at how word of mouth travels. Really good pitchers stick out, coaches talk and strong summer ball programs and scouts find them.
But why wait? Ask around, do some research and figure out who the strong travel ball/summer programs are in your area...then ask for a tryout for one of them that fits your budget and location. Good programs are always on the lookout for good pitching.
If you believe your son to be a college or pro prospect, it is important to separate the summer programs. In our area, there are a lot of teams that call themselves "travel ball teams" but never venture outside a 50-100 mile radius. This will not fulfill what you're looking for in most cases. You should find a program that has been around for a few years
or one that is stacked with a number of well-regarded players. You want to find a team that travels to meaningful events (e.g. tournaments in East Cobb, Georgia, Junior Olympics (if 16 or younger) and/or Perfect Game events, AAU National tournaments etc...).
Good luck! There are some good posters on here from your area and I'll bet they'll be around shortly to help with more details.