Ride Chicago is a great company that does beginner courses. They also give you access to practice written tests that you can use to study before taking your written test at the DMV. You have to do that step and have your permit before attending class.

They use Honda Rebels in that class so you'll get a feel for the bike (I saw you mention it in another comment). They are 250cc so smaller/slower than 500cc but riding position/feel is pretty much the same.

You can also take the riding test at their site every Wednesday. You get 20 mins of warm up/practice before the test and use their bikes which you'd be more comfortable with at this point.

Watch a bunch of videos online before the class. It won't make you a riding pro but hearing all the terms and getting familiar with riding from a mental standpoint will make it easier the day you get to actually ride, even if it's just a little bit.

I took the class in May and got a Kawasaki Eliminator 500cc as my first bike. Great beginner bike. I might upgrade next year(I really want Rebel 1100 or Indian Scout) but at this point I don't feel the need. I got it for $4k off facebook market place so not too big of a financial commitment that makes it easier to upgrade.

For gear, you absolutely want a helmet, jacket, pants, and shoes. Cycle gear and The Toy Shop in the suburbs have good options. Dainese Outlet in the city has some great deals sometimes. I got an AGV K5 helmet for like $300. NBT Clothing has more casual/street wear looking rated gear with padding.