l am wanting to go camping with my boyfriend for Memorial Day weekend, but neither of us knows a good place to go camping.l do not know if there are any free camp grounds anywhere, but that would be great if anyone knows of one!If not, any other camping place you know of would be great!Thank you so much!(Oh, I've heard of Priest Lake a lot, but have no clue where it is.....is that a good camping place?)

l live in the same state.
I'd go to Sun Lakes. its on the outskirts of spokane.
go here to learn more!
http://virtualguidebooks.com/Washington/EasternWashington/SunLakes/SunLakes_TOC.html
and:
http://bootsnall.com/articles/05-11/sun-lakes-state-park-coulee-city-washington.html

There are some nice campgrounds north of Spokane close to colville- Priest lake is in North Idaho.

Check out the Colville National Forest, you should find some info there. Have fun