Car travel advice needed!!

Hi so I’m 19 f and I’m going on a ten day car trip with my bf. 18M. We both live in Utah and plan on driving up to Washington through the Idaho route and back… we’re going all the way down to Forks and then to Washington National forest and back home. We each budgeted to have around $1000-$1,200 for gas and food etc. we’re camping out of my car which I just finished building out. I own a car that gets around 16-19 mpg. Will that be enough money?? I’ve never traveled without my family so I’m a bit nervous but I really want to do this trip!