In Chicago too. Here's a couple things to help you get started.
If you feel like being competitive, check out the Gladiator League, its a flex singles league and the number of members has grown, I've literally compiled a good group of people to hit with through that league itself.
Park District summer league has just kicked off too if doubles is your thing.
For Indoor tennis hit up McFetridge or XS Tennis, both are the least expensive options. XS is good for coaching, McFetridge also has a hitting group on Tuesdays and Thursdays I believe.
Or, if you just feel like hitting, feel free to shoot me a message and I'll gladly meet with u.