Hello Zoe, some ideas for places to stay, The Beverly Garland Hotel in Universal City Ca is close to Universal studios and Citiwalk and is in a nice area for lots of things and located in the middle of So Cal. The Super 8 motel in Monterey is nice too and not overly priced. The Best Western Zion Park looks really nice and wow what a view,or the Majestic View Lodge both in Springdale Ut are in an amazing location Also a night in Vegas is also an option and tons of nice places there and from the looks of your map you have about 6 to 8 hours of driving between places your going to stay. enjoy and post lots of pics ok.
www.majesticviewlodge.com
www.utah.com/lodging/lakepowell.htm
www.beverlygarland.com
www.monterysuper8.com