Hi Denise!
How exciting to end your road trip at the Happiest Place on Earth!
There are so many magical things happening at the
Disneyland Resort this time of year! I'm sure you'll be incredibly glad to have made the long journey!
In terms of your
Park ticket, if you have a one-day pass, the period of validity for that ticket starts when the Park opens and ends when the Park closes.
This means you can exit and re-enter the Park at any time during the period of validity, as long as you have your ticket as well as a hand stamp which will be given to you before you exit.
Generally, the same rule applies to parking at the Mickey & Friends Parking Structure. If you purchase a parking ticket, you can generally exit and re-enter the parking structure any time on the day the ticket is valid.
I hope this answers your question.
Have a Magical time!
-Anabel M.