Cincy has great trails to explore! Check out these trails on All Trails: Ault Forest Loop Trail, Eden Park Outer Loop, and French Park.
There's a few 5Ks on 9/27 in the Cincy area! Sonder & Friends Oktoberfest 5K (https://www.runguides.com/event/17640/sonder-friends-oktoberfest-5k) and Steady Strides 5K (https://parkinsoncincinnati.org/steady-strides).