Hi Keshia,
My family collects both pressed pennies and autographs from characters. Looking for the pressed penny machines around Walt Disney World and finding pennies that we do not have has become an adventure, and having photos with and autographs from characters makes a great keepsake of your vacation.
We do have a couple of the pressed penny books which we have bought at Walt Disney World. They are sold in many Walt Disney World merchandise locations. My thought for you as to the best bet for where to get one, along with an autograph book, as you begin your magical adventure at Magic Kingdom, is the
Emporium. This is the string of stores along the left-hand side of Main Street, U.S.A as you enter the park. When you enter the Emporium, I suggest that you find a cast member and ask them where to find the pressed penny books and autograph books. If by chance they do not have any at the Emporium, the cast member can help you to find a merchandise location where they would be. Since the Emporium is pretty much right on your way into the Magic Kingdom, and is the largest merchandise location in Magic Kingdom, I think that this is your best bet.
I hope that this information is helpful for you, Keshia! Have a great time planning your vacation, and please do not hesitate to ask if you have any further questions.