The glass museum is cool. A day walking around Pike place market and the aquarium is fun. The superwheel is pretty iconic and of course the space needle. Visit the Freemont Troll. There is a pop culture museum that was fun and there is a tour of the tunnels… make sure there is nothing in your vehicle to tempt thieves and be prepared to pay for parking, admission fees and for goods at the market. Enjoy the coffee and the wine and the local microbrews. Seattle has great fusion cuisine and friendly people. I always buy an umbrella when I visit Seattle even though I grew up in the PNW and almost never use it. It’s just a thing in my family. Take lots of pictures and talk to the locals.