Hi Stephanie, welcome to planDisney!
You bring an excellent question, and I'm glad to help! You can exit and reenter both parks, but reentry is always subject to theme park capacity. If a theme park has reached maximum capacity, reentry may be temporarily paused until capacity opens back up. In my experience, I've only seen reentry become temporarily paused during New Year's Day. I've visited during other holiday weekends, such as the weekend you are planning to visit (Labor Day weekend), and I did not experience capacity being maxed out. With that said, it's great that you chose to purchase park hopper tickets! In the worst case, if one theme park reaches max capacity, you can always go to the other theme park and spend time there until capacity opens back up.
I truly hope you're excited about your visit because many amazing experiences have returned to the
Disneyland Resort! The traditional character meet and greets are back, which means Mickey and all his Pals are ready to give out the best hugs and sign your autograph books. And many of the fantastic nighttime experiences are back as well! You can catch
World of Color at
Disney California Adventure Park, and my personal favorite,
Fantasmic! at
Disneyland Park!
If you have any other questions, please visit us again!
See ya real soon!
Jin