Hi Gabriela,
The most economical resort hotels are Disney Value Resorts. The four Value resorts are All-Star Movies, All-Star Music, All-Star Sports, and the Pop Century Resort. My favorite Value resort is Pop Century. It has a theme that most young guests enjoy and the food court there is fabulous!
You can price your vacation on the main Walt Disney World site. You can also work with an Authorized Disney Vacation Planner. They are travel agents specializing in Walt Disney World, Disneyland, Disney Cruise Line, and Adventures by Disney.
You should also consider the Quick Service Disney Dining Plan and the standard Disney Dining Plan. You can get more information on them
here. You can save money using the plans depending on how you dine.
If you want to consider a Moderate resort, I highly recommend Port Orleans - Riverside. My entire family loves the Alligator Bayou section of that resort. It has a Table Service (full service) restaurant and a food court on site. The pool area is also great with a relatively long slide.
Finally, be sure to make Advanced Dining Reservations (ADRs). They can be made 180 days in advance. Most first time guests don't realize reservations are important, especially during the busier times of the year.
Enjoy planning your vacation and write back if you have any more questions!