For all state scholastic events, you can find more information at http://ohioscholasticchess. org/
For almost all of the above events, please see http://www.ohchess.org/ for more information.
Free Events around Columbus:
Mondays: Worthington Chess Club: http://www.worthingtonchess.com/
Fridays: Fellowship of the King Chess Club: http://neilley.com/chess/
Saturdays: Mulligan Chess Club: https://www.meetup.com/mulligan-columbus-chess-club/
Check out ohchess.org for upcoming scholastic and open events.