a good strategy might be to look into a touring plans subscription. It will help with the time management of your trip.
Go to the library and get one of the planning guides even if it is a couple years old. Read it cover to cover.
As you get into the planning process - read posts here, search for post and ask lots of questions. There are so many facets to planning a trip: Dining reservations, when to go, who you are going with, the interests/priorities of the party going, budget, resorts, fast passes. It can be overwhelming. If you have never gone then do not try to plan a trip less than a 9 months - a year out. You need the time to figure everything out- from if you want table service or will you be happy with quick service. Hard to get dining reservations (BOG, CRT, Ohana) need to be done at 6am when you hit 180 days from your trip.