I would like to know if there is someplace in Peoria to sign up for the license sticker discount for low income seniors?

I did a bit more research for you. at cyberdriveillinois.com
Illinois Department on Aging 800-252-8966 or www.state.il,us/aging
Good luck

Go to your local Senior Center or Senior Services they can help with the application.
You could also call a great organization called Elderwerks 855-462-0100 or Elderwerks.org they are a non profit corporation and their sole purpose is to help with all aspects..Housing, Education and supportive referrals.