Welcome!
Best bet is to try your region or division's website.
Looks to be quite a few races at Mid Ohio and Nelson Ledges this year.
greatlakes-scca.org http://greatlakes-scca.org/calendar/racing
From Fort Wayne, head east on US-30 and you'll damn near run right into Mid-Ohio Sports Car Course near Mansfield, OH. Probably a 2-2.5'ish hour drive.