Hi Tamara,
Thanks so much for visiting the Disney Parks Moms Panel with your question.
I have great news for you. Everything that you asked about is possible! You are still a guest at Walt Disney World until 11:59 p.m. on the day that you check out. Bell Services at your Walt Disney World resort will be happy to store your luggage for you after you check out and before you depart. You can continue to use the pool at your resort, and your Disney Dining Plan credits will remain active until 11:59 p.m. on the day that you depart.
I am not sure how you are traveling to Walt Disney World, but let me make a suggestion if you are flying. You can take advantage of
Resort Airline Check-In Service, which will allow to you to check in for your flight from your Walt Disney World Resort. You can even check your luggage, and it will be taken to the airport for you! Check out the link I provided for further details.
I hope that this information is helpful for you, Tamara. Have a wonderful time planning your vacation, and please do not hesitate to ask if you have any further questions!