Hi Randi,
Welcome to planDisney. You have less than a month until your trip – how exciting!
Based on your question, it sounds like you purchased a
Park Hopper Ticket. A Park Hopper Ticket allows Guests to enjoy the magic of both
Disneyland Park and
Disney California Adventure Park on the same day. Guests with this ticket option will need to select a starting theme park and will then have access to the other theme park starting at 1PM.
In my experience, one of the theme parks reaching capacity is extremely rare -- something seen only during major holidays or events such as New Year's Eve. This rarity is even less likely with the new reservation system. Therefore, I do not think you have anything to worry about.
While visiting both parks during your trip, make sure to snap a picture in front of both park’s most iconic locations: Sleeping Beauty Castle in Disneyland Park and Pixar Bridge at Disney California Adventure Park. You can even consider using a
PhotoPass photographer to capture the memory better.
Have fun,
Lola