The earlier you start to "market" yourself, the better. Sophomore year is the ideal time, and definitely no later than junior year.
NCAA schools can start sending you questionnaires anytime you are in HS, but they can begin sending you personal letters, golf recruiting information and info about their program Sept 1 of your junior year.
You cannot receive telephone calls from NCAA until after July 1 AFTER junior year, but you can call a coach anytime, including now (but if they are not there, they can't return your calls).
You can send and receive e-mail.
NAIA schools are not bound by those rules, and can contact you in anyway, at anytime.
The earlier college coaches begin the evaluation process (even just monitoring your scores, tournaments, etc.), the better chance you have at finding the right school.
ALSO: AJGA and other summer tourneys are more important than your high school accomplishments. You should try to find info on where you can play next summer, at the highest possible level amateur tourneys.