Hi Anita!
Hooray for your upcoming trip to the Happiest Place on Earth!
At this time, stroller rentals at the
Disneyland Resort are available on a first come, first served basis. Although I've never seen a complete stroller outage, I would recommend that you head to the
stroller rental office as soon as you arrive at the Park.
The stroller rental office is located outside of the
Disneyland Park main entrance.
The earlier you arrive, the better chance you have of making sure you have your stroller ready to go for a Magical time!
Now, if you're really concerned about stroller availability and feel like you would benefit most by booking something in advance, there are a number of third-party companies that offer stroller rental deliveries for guests of the Disneyland Resort.
Although these services are mainly offered to guests staying at one of the three Disneyland Resort Hotels or other area hotels, I'm sure you can make arrangements if you're only planning a day trip. The companies that provide advance stroller rentals are City Stroller Rentals and Traveling Baby.
I hope this helps.
Thanks for stopping by the Disney Parks Moms Panel!
-Anabel M.