How do I get my son recruited for D1 football?

He is a 6’0 180lbs high school junior starting FS with 4.3 speed.

Take him to the closest Nike SPARQ or Rivals combine in the winter/spring. Both are free. If he runs a sub 4.5 there, and is measured at 6ft or better, tons of schools will come calling

Considering that 4.27 is the fastest 40 ever ran at the NFL combine your problem will be too many offers.