Team Stradale based out of Autobahn offers driving schools in their cars: Rent & Race - Team Stradale. T.J., Lotus Mechanic Extraordinaire, now works there so I'm sure he can get you any info that you need. His screen name here is twaszak1.
Another option are the Lotus Corps events. You just missed it, but just did the Drivers Education track day at Blackhawk a couple of weeks ago. Great guys and classroom and an instructor rides with you. Learned a ton.
Yes, it's your car, but hey, allows you to learn your car!
Another option is to join up on some Spirited Drives - we do a ton! Lots of twisty roads, speed, etc. You won't get an instructor, but you'll really have fun in YOUR car. The LotusCorp one is this weekend (Sat/Sun overnite) - I'm only going Saturday, but it will be tons of fun. Starts in Rockford. Check the 'Chicago Drives' thread.
one data point to consider is cost. Bring your own car and the cost can be as low as $300 for the day. Use somebody elses and you can add $1000 to the per day cost, which is quite a bit for someone dipping their toe in the water.
I'd advise forgoing the worry and using what you have, be it at a track day or at an autox. Alternatively, you can show at a track day/autox and ask for a ride. It won't be the same as driving, but maybe it will help answer questions/concerns about what a track day is and if its something you'd be interested in.
We've got some great, low key, professional quality instructors. No one will push you to go faster than you feel like, or to do anything you're uncomfortable with. This is a great way to get started - a very safe place to do it at - and a great track to start off at.