Definitely need a list, reach out and assume it's a part time job, but 8th grade is far too early IMO. I always think how would I react, if I were the coach, when communicating. Think my eyes would roll inside my head if I was receiving outreach from 8th graders. 
I sent my son to a camp at UCONN October of his freshman year, just for the experience of being on a college field (no Idea at the time it was a recruiting/$ tool). Coach Penders told my son he was the youngest there by 1.5 years. TBH, it felt kinda silly being there, when my 14yo son was mixing up with 17/18yo...and he's a D1 commit.
I was ignorant then but it all worked out. Never did I think about college recruiting at such a young age. I would give it time and just make sure you prep him for HS and the demands that go along with it. You have plenty of time...heck many of the coaches you reach out to may be gone in 5 years.