Lucia, your little one is going to have a really exciting time at Walt Disney World for the first time. You will absolutely love watching all the magic through his/her eyes. Depending on your toddlers age, you will not need to purchase a ticket for him/her. Ages 3 and under do not require admission into the parks and can also eat for free.
There are so many activities for little ones that I probably can't reference them all, but some of my favorites are character meet and greets throughout the parks and some resort restaurants. My kids are huge fans of the characters, however, some little ones can be a little hesitant when first encountering them, so just take the cue from your child and don't force it if they become over anxious. My next suggestion would be the
Kidcot Fun Stops in Epcot. This is a really fun way for your kids to enjoy the different countries without getting too bored. That way, you can enjoy the different cultures while entertaining them, too. Around the different parks, there are also play areas with play structures so they can run off some of their energy in the middle of a long day. There is the
Casey Jr. Splash and Soak Station near Dumbo in Magic Kingdom or the
Boneyard in Animal Kingdom. Another fun spot for wee ones is the Affection Section at Rafiki's Planet Watch in Animal Kingdom.
I think the fireworks at all the parks are fantastic, but I would probably recommend going to Magic Kingdom for their fireworks since it is my favorite backdrop for those amazing shows.
Have a magical first visit!
~Allison L