First off safe travels to you and your family as you make your way to Orlando.
Welcome to Universal. You all will love it. There are rides for everyone.
Take a look at the maps of the parks on the Universal Orlando Website. This will help familiarize you with the parks. Look at Plan Your Visit drop down: All the rides are listed also along with the height requirements, Park hours etc.
Also under the Things To Do drop down: All the restaurants are listed for you to get a look at the menus.
There are 3 Parks 1. Universal Studios, Islands of Adventure and 3. Volcano Bay (the water park).
Since you are not staying onsite you will not be able to get into the parks 1 hour early. So I would be there at rope drop to get the most out of your time in the parks.
Park to Park tickets are required to ride the Hogwarts Express between the Two Harry Potter Parks. Hogsmeade (In Islands of Adventure) and Diagon Alley (In Universal Studios).
You will see on the park hours that Universal Studios is closing early on Thursday at 5 pm. This is because
HHN (Halloween Horror Nights) is presently going on at Universal Studios on Weds, Thurs, Fri, Sat, Sun. You will want to keep that in mind as you look at your time in the Parks.
The Parks are going to be busy with HHN going on. Lines could be long as a result.
There are Express Passes that can be purchased that allow you to skip the regular lines at IOA and US. Regular Express pass allows one express ride per ride. Unlimited Express allows unlimited rides on all rides.
Those in the family who get motion sick should avoid Forbidden Journey in Hogsmeade. Flight of the Hippogriff is located there also by Hagrid's Hut. Small coaster should be fine.
Simpsons ride at Universal Studios is another stand out for motion sickness.
Hulk Roller Coaster in IOA, RRR and Mummy are coasters that will give you a good run for your money so if you don't like coasters you won't like these.
They have Ollivander's Wand show at both Hogsmeade and Diagon Alley. I like the one in Diagon Alley better.
There are magic tricks that can be done with the interactive wands in both Hogsmeade and Diagon Alley. The wands are sold in the Universal Store in CityWalk and in the shops in the parks.
The family feast at The Three Broomsticks is a meal that will fill up a family of your size at a great price.
You can request free cups of ice water at any area they sell drinks.
Refillable popcorn containers are a great price to keep the kiddos filled up for a good price on the snacks.
They also sell refillable coke cups that might be an option also.
You will be wowed by the Harry Potter Parks.
This will get you started.
Have a great time at Universal