Hi again Zoe, we are all from the UK here so that doesn't necessarily mean it will only be the once
Anyway, you are staying onsite at Disney. Will you be hiring a car? If not, do you only intend to do the Disney parks. If you have the quick service dining plan, you do realise that you would have to pay extra for the Aloha Dinner Show, don't you?
Check out
www.allearsnet.com for dining menus, they will say whether a restaurant is Table Service or Counter (quick) Service so you will have an idea of what is included.
If you haven't already done so, set up an account at
www.mydisneyexperience.com and customise your MagicBands and link your reservation as you will be able to make FP+ reservations very soon. You can make 3 FP+ reservations at one park on each day of your visit. Once you have used all three, you can then make further reservations, one at a time, using the kiosk in the parks.
If you only plan to do the main Disney parks, you will have plenty of time to see and do a lot of what is on offer.
My main advice would be not to try and cram in too much but I would definitely recommend making some time to visit Universal and Islands of Adventure.
Depending when in August you are visiting, you may find the parks are quite crowded. It can also be incredibly hot and humid in August so the best thing to do is hit the parks early, take a break around midday/early afternoon and then return to the parks in the evenings when it has cooled down a bit. The parks will be open longer in the summer months so you can benefit from the longer evening hours. The general consensus is to avoid parks with EMH (extra magic hours) or, if you intend to visit a park with morning EMH, make sure you get there early (when EMH starts) or you will have lost the advantage.
Again, feel free to ask more specific questions if you have them.