You need to watch a lot of videos on yT. There are millions! There are videos covering all the different hotels. And videos covering all the different restaurants. and all the different parks. Etc. Buy yourself the latest copy of the Unofficial Guide to Walt Disney World from a good book store. It covers all the parks, rides, restaurants and resorts.
Not sure if mentioned, but all of the travel options within the park are all free. That's why it is frequently called "the bubble". And three of the parks have hotel options that are walkable, e.g. Grand Floridian to Magic Kingdom park (MK). And a few hotels walkable to Epcot and Disney Studios.
The next really important question is who you are travelling with, what excitement factor you can tolerate and what your expected budget is. This will determine if you should even base yourself at Walt Disney World (WDW) or base yourself at Universal Studios Orlando (USO) instead, and spend a few days at the other.
Lastly, for now, WDW is struggling and offering great deals on packages where your dining is included free on top of other benefits. That's quite a discount.
Very lastly, little children will often say that the best part of their WDW holiday was the hotel pool. Think wisely before setting your expectations!