Here is how I plan. I am an early riser, so plan to be there when the park opens
1. Which park do I want to go to? How many times at 1 park? Look at park hours to decide which park is best for each day.
https://media.disneywebcontent.com/StaticFiles/ParkHours/WDW_TAC_2017oct.pdf
Make a list of park for each day.
2. What rides do I want to ride? Maybe watch youtube videos. Plan to get fastpasses for those rides. A little research on which rides are the hardest to get fastpass. So they would be the 1st fastpasses I try to get. Each fastpass has an hour window to use it.(Your park tickets must be on your "My Disney Experience" web site with your resort reservation.
3. Do I want to eat at the park? Do I want to go to a restaurant that requires reservation? Or eat at counter service( they have places to sit down. Sounds silly but my newbies thought they had to stand up to eat).
4.Anything special I want to do? EX: go to water park, go to Disney Springs for shopping, eat at another resort..
This should get you an idea to plan the vacation. BUT, you don't have to stick with this when you arrive.
Have a great time!
(Sorry if this contains info you already know, I'm an old teacher!!)