Liberty Theater—just took a shot at this time
“Music, dance, theatre, and one magnificent chandelier.” You can rent it for your event, too. I called ahead to check on accessibility, and was told it is accessible. For events and tickets, see https://libertyastoria.org/
Other Arts venues are the Astor Street Opry Company http://asocplay.com/ , and
Clatsop Community College Performing Arts Center (PAC) https://partnersforthepac.org/
Flavel House—not wheelchair accessible, but the exterior is worth seeing if you can’t go in. 441 8th St.
If you Google “flavel house museum astoria or”, then click on the little map associated with the Wikipedia box at the right of your screen, you can get a map that pinpoints lots of places in Astoria.
Oregon Film Museum—not wheelchair accessible, across from Flavel House on Duane St.
A peek inside: video at http://astoriadowntown.com/
Riverfront Trolley—not running through the winter 2020; see http://www.old300.org/
Museum of Whimsy—was closed for the season, https://www.museumofwhimsy.com/
Uppertown Firefighters Museum—was closed for the season; contact CCHS for hours http://www.cumtux.org/default.asp?pageid=9&deptid=1
Astoria Victory Monument (WWI Doughboy), intersection W Marine Dr & Columbia Ave, https://scholarsbank.uoregon.edu/xmlui/bitstream/handle/1794/23251/Yeley_SAHMDR_2018.pdf?sequence=1&isAllowed=y
More info on Astoria, and events (check for updates) https://www.travelastoria.com/trip-ideas/
Also, Scandinavian Midsummer Festival June 12-21, 2020 www.astoriascanfest.com
Columbia River Eco tours https://www.columbiariverecotours.com/
Astoria Underground Tour https://www.oldastoria.com/
Astoria 2nd Saturday Artwalk, http://astoriadowntown.com/ scroll to bottom home page for map
Astoria Sunday Market May-Oct https://www.astoriasundaymarket.com/about
Fish off downtown piers, if you have an OR fishing license and property owner’s permission; parks OK
I am researching this further, and will include on my “Goin’, Goin’, Gone Fishin’” post later
I've been in a wheelchair for 30+ years. It poses some challenges for traveling. Maybe others can benefit from my experiences.