Have you seen this site yet?

https://www.planetware.com/washington/top-rated-things-to-do-in-gig-harbor-us-wa-179.htm

And this one has a very eclectic list of things around Tacoma

https://www.busytourist.com/things-to-do-in-tacoma-wa/

I'll put a plug in for the Washington State History Museum. If you're into that sort of thing, it is pretty expansive.