Disney would like for you to pay for everything in the parks (and with the way they are going, I'm sure they will one day) but there are a lot of fun things that you can do while you are there that are either free or don't cost much. If you are staying at the park, why not take a Resort day instead of just running through the parks every day?

Nothing screams "Disney" like the Magic Kingdom which is based off of Disneyland. Their fireworks must be seen at least once a trip (currently working on a article for all the best viewing spots for all the fireworks). The best viewing spot for the fireworks for the Magic Kingdom are not in the park itself but outside. The top viewing spots are:

Cheap-ish but best view: California Grill - pop up and have a drink or an appy, keep your receipt, and head back up at Fireworks time. You can stand on their roof to watch the fireworks and they pipe the music in as well

Free: watch from the Ticket & Transportation Center (just to the right of the entrance to the Ferry to the Magic Kingdom)

Free: Watch from the beach at the Polynesian Resort. They sometimes have smores roasting ($6) at the same time

While there is a drawing class in the Animal Kingdom (book a fast pass, it does fill up) there are sometimes free classes held outside of the park as well. Just check with the hotels directly for more information but usually Art of Animation holds multiple ones for resort guests. As of 2021 it does not look like Art of Animation is holding these classes - check before going.

While the campfire is cheap, you can purchase a smores kit to enjoy as well. This is a fun way to relax for the evening and possibly meet some characters!

Chip ‘n’ Dales Campfire Sing Along – nightly campfire at Disney’s Fort Wilderness around 7 / 8pm. Here you’ll get to visit with Chip & Dale

Campfire on de’Bayou – nightly at Port Orleans Riverside with storytellers and entertainment (usually before or after their nightly movie)

Animal Kingdom Lodge – nightly campfire just outside the main lobby with a storyteller

Not many people think about the resorts or exploring them but there is a lot of history, planning, and amazing detail that goes into them. Stop by the hotel's front desk to find out when (and if there is a cost) they are happening.

The Wonders of Wilderness Lodge (at Wilderness Lodge): open to everyone, 1 hr long. Gives the backstory of the resort & villas. One of the most heavily themed resorts in Disney’s collection. Meet at the Grand Canyon Fireplace in the lobby at 9am (sometimes this changes so check with the front desk)

Self-Guided Yuletide Tour: runs during Christmas time and takes you around to the various resorts to enjoy their Christmas decorations

Legend of Conch Flats (free): 45-60 minutes to explore the hospitality house from Papa’s Den while you learn about how they themed the resort. You’ll get to try food at Olivia’s and a pin

Florida Express ($15/person - 2020 price): 1 hour long walking tour at the Grand Floridian about the history of the resort and a visit to Victoria & Alberts

There are also wandering entertainers on the boardwalk and various hotels have lounge / lobby entertainment (ex. the Grand Floridian has the Grand Floridian Society Orchestra by the Mizner's Lounge).

Did you know that there are hundreds, if not thousands of Mickey's hidden all over the park's and hotels? There are so many that people keep forgetting where they all are! Before coming to the park you can pick up various books about the hidden Mickey's and go on a hunt to find them yourselves or if you'd prefer, the Wilderness Lodge has a Hidden Mickey Scavenger Hunt and all you have to do is ask for it at the Front Desk.

Almost every resort puts on Movies Under the Stars where they will setup a screen on their lawn and play various Disney movies. They resort changes nightly usually but you can see what is playing and when when you check in at your front Desk. When we stayed at Port Orleans they also had small fires where you could smores roast while watching.