Hey there Jade,
Welcome to planDisney and thank you for your question - you've definitely unlocked a hidden achievement here for finding ways to maximize your stay at the Disneyland Resort!
You absolutely can check-in and enter the parks for
Early Entry on the first day of your stay at a
Disneyland Resort hotel. This is one of my favorite tips to share with people that is not a secret but I find many people don't realize!
As you mentioned, your room will likely not be ready, but you can go through the check-in process, drop our luggage off at Bell Services, and then head into whichever park is hosting Early Entry that morning. When I've done this on previous visits, the Cast Members inside the park typically just ask to see my hotel stay information in the
Disneyland Resort mobile app since my room key wasn't ready yet.
Keep in mind that one park hosts Early Entry each day and it can switch off throughout the week, so keep an eye on the
Hours & Events Schedule to see which park will be offering Early Entry for each day of your visit. This schedule is available about six weeks out from the current date, so you'll be able to see your dates once you're in that six-week window.
Thanks again for your question, Jade! I sure hope you enjoy your visit to the Happiest Place on Earth!
Have a Magical Day,
Greg