This summer my sister and I drove from our hometown in Maryland to to Los Angeles. We stayed in Denver for a few weeks and in Los Angeles for a month. It was the most spontaneous and amazing experience of my life and I would recommend it to anyone and everyone!
If you visit the Denver area, going to Boulder is a MUST - that was my favorite town we went to on the whole trip! Tattered Cover Book Store in downtown Denver was the coolest bookstore and Urban Farmer had the most aesthetic bar. 10/10 would recommend.
Los Angeles was a DREAM. So many cool places to discover. My sister and I loved all of the basic touristy stuff - Griffith Observatory, the Hollywood Sign, Melrose Ave., Disneyland, etc. - so those are a must! Buuuut some not-so-popular places we fell in love with are Redondo Beach, Harriet's Rooftop for brunch, Rooftop Cinema Club for a drive in movie, and Lazy Bird for the best acai bowl of all time!
And you can't forget the farmers markets that are on every street corner on the weekends. Cali's markets are top tier.