There is a lot of information on this site about HA D3 recruiting. Some things to think about:
- where has he played in the last year (I know with coronavirus, it may be not much)? Does he have any coaches (travel or high school) who are willing to help you with this? Have you asked them what they think? Having coaches make contacts with schools, if they are willing and/or if they have connections, is the best way to get college coaches to take a look at you.
- do you have video of his pitching? If so, whether or not you are able to go to Headfirst or similar showcases, you can send introductory emails to coaches, with a link to the video. If his velocity was verified by a showcase, say so; if not, try to get video with a radar gun in the picture. With all the difficulties with travel this year, video is apparently even more important.
- At schools that are selective, the coach can help your son with admissions, that process is picking up NOW, at the beginning of August, and they usually want you to apply Early Decision in November. So, if those are the sorts of schools that are of interest, you need to be contacting the coaches right now. At other schools, if your son can get in on his own, then there is more time, schools recruit all the way into the regular admission cycle.