Go to the events where the schools on your son’s vetted list will be. And those events should be ones where he will be seen by those schools.
Vetted academically and athletically. At a minimum, trusted third parties (e.g., scouts, guidance counselors, et. al.) have said your son could be admitted and could play baseball there.
Does he have a vetted list that he’s working now? If not, he should ASAP.
For the vast majority of players, college baseball recruiting is not a crap shoot where a player hopes to be seen by random coaches at some massive tournament and then get offers to play. It’s about putting together a realistic list of schools and then getting in front of those coaches (and oftentimes admissions reps).
It’s also about connecting regularly with those coaches on the vetted list (and again, oftentimes admissions reps) via phone, text, email, and in person.
Good luck!