Whether you are coming for a few days, or a few weeks, the Pacific North West has countless wonders to be found.
Here are a few links to some ideas if you want to explore Seattle whilst you are in town:
https://www.tripadvisor.com/Attractions-g60878-Activities-Seattle_Washington.html
If you feel like getting out of the city and exploring the amazing nature that is all around it, here are some ideas for hikes or natural spots to check out:
https://www.panpacificseattle.com/blog/seattle-day-trips-for-nature-lovers/
https://www.roadsanddestinations.com/2019/06/18/the-top-5-natural-attractions-near-seattle/