Your first trip to Walt Disney World!
First, since you are already going for 4 nights, you may want to look in to the
buy 4 nights, get 3 nights FREE package deal. I generally purchase the components of my trip separately in order to save money but this is the best package deal that I've seen in years.
Of course, staying longer does mean more meals and perhaps your schedule doesn't permit that amount of time for an escape.
For your first trip and with only five days, I would not purchase the water park option. For relaxing water-side time, spend your afternoons at your hotel pool. In June, you'll want a mid-day break out of the hot sun.
For shorter trips, I think you can save money by doing the "one park per day" method. You'll have more time actually in the park rather than having to schedule in travel time. In order to use this touring strategy, be sure to schedule your park days wisely. Do not go to a park that is hosting morning or evening Extra Magic Hours, for example. Avoid where the crowds are headed.
If you purchase a five day park hopper, you will will get five days of touring. Each day that you first enter a park, you will have deducted a day's park admission. You may leave and return to that same park within that day as many times as needed (unless you have the park hopper option, then you can hop to another park within the same day too).
Touring Monday (no matter how long that you stay) and again on Friday will require two days of Magic Your Way tickets.
Each day that you FIRST enter one of the theme parks, you are deducting one day of park admission from your allotment.