There are amazing things to see and so in and outside of Seattle. Don’t be afraid of exploring. That being said, keep away from 3rd and Pine.
Pike Place, the gum wall, ferry ride over to Bainbridge or any other island, Chihuly Glass, MoPOP, Space Needle (only if it’s a clear day is it worth the price, in my opinion), harbor boat tour…I could go on and on. You can get a city pass which would save you some money. https://www.citypass.com/seattle?mv_source=rkg&adpos=&creative=617830560396&device=c&matchtype=p&network=g&gclid=Cj0KCQiA6rCgBhDVARIsAK1kGPKisoJAdBtKc7iODC6cuKNUNAFb7P9-jLMq1IF1Sc-fjwJQeLkhC9EaAvnYEALw_wcB