Welcome to Canada. British Columbia is a beautiful province.
If you are staying in Bothell, WA then the quickest route to Canada is I5. Vancouver has lots to see and do. 4 hours to the east via Hwy 1 and Hwy 5/97C puts you in the Okanagan. Osoyoos to Vernon is one of the nicest drives in the province.
Wine tours are big in the Okanagan and then do a circle route to Kamloops and back down the fraser canyon Hwy 1 to Vancouver.
You can fill 4 days easily on this route.
Have fun!!