The ACA has local chapters, including one in the Chicago area, as well as a national office. Check with ACA to find out more about classes in your area. FOCR is a good place to pick up the basics on a less formal level. You can sign up with or without a canoe or a canoe partner. If you're inexperienced or a complete novice, FOCR will assign you to a more experienced partner.
Some trips lend themselves to beginner practice more than others.
For example, you may not want to be in the main branch of the Chicago River dodging sightseeing boats if you don't yet know how to handle a canoe. Though Friends of the River trips are not formal classes, the guides will help you and give you tips, and you can pick up some very useful coaching. You don't have to have a partner to sign up, nor do you have to own a canoe. The Young Sierrans also used to offer canoe instruction, but I haven't seen their publicity materials in a while. You can check local outdoor magazines for more listings of local canoe clubs and what they do.