What should I do and bring before I make my 6 hr road trip ?

the coolant on my car right now is at about half or lil bit higher. I was wondering what i should bring in preparation for my 6 hr drive, and i will be goin tru a 1-2 hr of ping a desert... and i have a 99 Avalon toyota and its in good condition..... do you guys think i will be able to make it??? im asking because this is the first time i will drive my car this far in my life and im the third owner of this car... has 113k mileage.