Congrats on your upcoming trip to lovely Aulani, Jcooper131! It is my very favorite Disney resort anywhere! There are a LOT of threads with fabulous info on Aulani, including some very good trip reports. Please do read these in addition to whatever comments you get here as they are very informative.
You most likely will want a rental car. We always rent and I usually find the best prices either on
www.discounthawaiicarrental.com or at Costco Travel.com (you must be a Costco member for this). I would go ahead and book the cheapest car you can find that you would be happy with and then just keep checking the rates as often the prices will drop as your dates get closer. But NOT always. Since Hawaii is all islands, there are a finite number of cars to rent on each island. If inventory gets low the prices will skyrocket. You can bank on that. So go ahead and grab a no-credit card guarantee rental so that you can readily cancel if indeed you do find a better price later.
I love AMA AMA for breakfast and lunch. Dinner was very nice as well, especially if you book a sunset time because the views of the sunset are amazing. I personally prefer the first 2 meals of the day there. Incredibly beautiful setting, great service and very good food, IMO.
There is truly outstanding live Hawaiian entertainment nightly in the 2 lounges, Olelo Lounge and Off the Hook. The Off the Hook entertainment is sometimes moved to AMA AMA, especially in inclimate weather. And do NOT miss one of the Starlit Hui shows! It is awesome! They generally perform this twice weekly during most of the year. (busy times they may do 3x/week)
I have stayed in ocean view accommodations on each of my 3 trips to Aulani and they are gorgeous. I've stayed in both the Waianae and Ewa towers and found the views to be sterling in both. I do not have a strong preference after staying in both.
If you have never visited Pearl Harbor, you will definitely want to either book an excursion through Aulani, or do like we did and go on your own. You can reserve tickets to the USS Arizona Memorial in advance though the rules are constantly changing on how far out you can do this. It only costs $1.50 each (or that's what it was this January) to reserve your ticket. We went early in the morning but be aware that rush hour traffic is a very real thing on Oahu. We got smack dab in the middle of it the morning we left Aulani at around 7:00am for Pearl Harbor. Allow a little over an hour to get there if you are driving into Honolulu on a work day.
Do a circle drive of the island to see the North Shore and the gorgeous east side of the island. The only palace on U.S. soil is Iolani Palace in Honolulu. The Bishop Museum there is also highly touted though I have yet to do that. It's on my list.
If you are a Costco member, there is a very nice Costco no more than a 5 minute drive back toward HNL. Great place to buy some poke or sashimi and some goodies for your kitchenette. And there's a BigTarget (not a SuperTarget) across from it.
Plan on some days to just enjoy the resort. The pools are amazing as is the lagoon. Oh, and the Laniwai Spa is in my personal Top 2 spas anywhere!! Very pricey but an amazing experience!
Happy planning!