You could of course celebrate with cake and ice cream. (Ice cream sounds particularly good during this heat wave.) The ADA National Network has some additional suggestions for marking this significant anniversary.
The Morning Edition show on National Public Radio is asking persons with disabilities to help them document how the ADA has impacted their lives. They accept written, audio, and video personal stories. Find out more about your opportunity to share here: https://www.npr.org/2020/07/22/893863351/after-30-years-how-has-the-ada-helped-you.