Hi there, Olivia! Welcome to planDisney. Thanks for bringing us your question!
It sounds like you have a fun trip planned with your pals! The only way to change your starting park would be to cancel your
reservation and make a new one, and I would not recommend doing that this close to your visit. It is probably not worth the risk that you might lose your reservation altogether. With a
Park Hopper ticket, after 1:00 p.m., you can move back and forth between parks as much as you’d like.
Once you arrive at
Disneyland Resort, you could check with a Cast Member at the Main Entrance Ticket Booth to see if they are able to share reservation availability. While there are no guarantees, they may be able to provide insight on if changing your starting park is an option, based on reservation availability at that moment.
Olivia, sending you a pinch of pixie dust with hope this gets sorted out in the way that you’d like. Fingers crossed!
Thanks again for stopping by,
Kamini