My best friend and I are taking a month of our summer break from college to drive from Vancouver, BC to Yosemite and back. We hope to do some sightseeing in cities and towns as well as get out into nature. Neither of us are from the west coast and don't have too much money to spend. This means that we want to do a bit of camping as well as crashing on floors and couches. We are planning to hit the cities along the way (Seattle, portland, the bay area) and obviously as many of the amazing parks as possible. But as for specifics we are a bit lost.

Any suggestions on cheap housing (like almost free), and towns/places/areas to visit or explore would be greatly appreciated as well as any general advice.

Oh and tips on seeing national parks too.