Hello there Taylor, and welcome to planDisney! How exciting that you'll be visiting the "Happiest Place on Earth" with your little Mouseketeer soon!
I also traveled to the
Disneyland Resort when my daughter was about 4 months old, and I found it was easiest to bring the car seat carrier with the stroller travel system. She was comfortable in it, it was convenient for travel, and she was able to take naps. My recommendation would be to bring the stroller that your little one is most likely to nap in so they can get some rest throughout the day! As long as either stroller is not larger than 31" x 52" you are fine to bring in either one.
I also want to let you know that there are
Baby Care Centers conveniently located in both
Disneyland Park and
Disney California Adventure Park. I used these frequently to feed the kids and change their diaper. They also have baby essentials for sale too in case you need anything during your visit. They are a wonderful place to take a break throughout the day!
I hope this information was helpful for your trip Taylor, and if you have any other questions please do not hesitate to
come back and ask!
Have a magical trip!
Melissa