I use to teach for adult education, I had beginner and advance classes, so check you adult education program with your town. This is one of the most affordable ways! My second recommendation would be a quilt shop. You can pick the project you want to work on and the shop owner can help you pick a class that meets your experience requirements. Quilt guilds are alot of fun, and I think you would enjoy a guild, but likely not for classes. The guilds that I have belonged to only had classes with the guest speakers, and they are normally only one day classes working on what that author selects. Although, in joining guild you can meet other quilters who often have mini sew groups that are always fun where you can get help from your new friends!
I hope you find something, classes are fun!!