For 2 days, Olympic National Park would be a good option. If you are going this weekend, it will be difficult to find a place to stay (including camping). You can stay in Port Angelos or Forks, both on Hwy 101. Port Angelos is the largest town in the area. Lake Crecent area (west of Port Angelos) has cabins and also beautiful place to stay. There are many Bed & Breakfasts in the area, another great lodging option.
If you go, be sure to go to Riato Beach, Moran, 1st, 2nd and 3rd beaches are the best. In my opinion, they are really the best of Olympic National Park, not to be missed. Hurricane Ridge, overlooking the Olympic Mountain range, is worth a visit. There are viewpoints along the way you can see many snow capped mountains in both US, Canada, and Puget Sound. There is a hot spring not too far from the west end of Lake Crecent. The Hoe rainforest (not 热带雨林), if you have never seen one, is not too far from Forks. But you really don't have to drive all the way there to see rain forest. There are rainforests within 1 hr or less of driving from Redmond.
You can't compare apples to oranges. And you can't compare Mt Rainier to Olympic National Park. If you go to Olympic, be sure not to miss the beaches.