Universal is really different compared to Disney in terms of planning needed. Universal Disney which can be really stressful for some people that like to "stick with a plan", Universal is totally different. At Universal, relax and enjoy the parks. There really is no need to get stressed out or create a big plan. You don't need to make meal res. unless you feel like you must. If you must, you really don't need to make them until that day. Just go to the place and make your res. for later that day.
Now, I will try my best to outline a plan for you. I have done this before for other guests and they seemed to really enjoy it. Hopefully you will find this helpful as well. Print out a park map and follow along with the rides as I tried to place them in order that you will come to them.
On May 30th:
Go to the Studios side of the park once you arrive. I assume you will not be arriving at the parks first thing in the morning since this is your first day, which normally means people arrive in the afternoon. Either way, I would start off with Shrek-4D and Dispicable (SP?) Me (which will hopefully be open by then). From there, work your way around the park hitting (in the order you come to them):
-Hollywood Rip Ride Rockit
-Mummy
-Disaster
-MIB
-Simpsons
-ET
-Terminator
I skipped a few rides here (like Twister). You really don't need to do these rides unless you have some time left over. Hopefully you will be able to get all of these done before the park closes (with some time to spare). They might be showing the new nighttime show at this time as well, which you will want to check out. They will also have the new parade going on, but again, no idea what time this takes place. Unlike Disney, Universal rarely posts show/parade times on the website simply because, again, planning is not really needed. If you want to eat a nice meal after you are done with the park, enjoy a nice meal on Citywalk. So many food options there!
On May 31st:
Since you said your hotel lets you get into IOA one hour early, get there early! You will see how long the walk is from the parking lot to Citywalk, and then the parks on your first day. If IOA opens at 9am, that means the park will open to you at 8am. Thus, I suggest arriving to the parking lot NO LATER than 7:30am. The sooner the better.
Once the park opens, just follow the group to the HP area. Take it all in during your extra hour, doing all of the rides and looking around all the shops. While you might not be able to see everything in your first hour, you will hopefully be able to see most of it. Your key focus should be FJ and then anything else that sounds fun that you want to do.
After you have finished everything in HP, work your way back towards the front of the park. You will be making a circle and end up back at HP. Here is the list of rides/shows you should try and see in order after you leave HP:
-Eight Voyage of Sinbad (show, skip it if there are no show times that work)
-All of the Dr. Suess area rides
-Hulk (for the kids brave enough and tall enough)
-Storm Force (like the tea cups)
-Dr. Doom
-Spiderman (don't miss this! Amazing ride!)
-Popeye (water ride, skip if you don't want to get soaked)
-Dudley (water ride, skip if you don't want to get soaked)
-Jurrasic Park River Adventure (another water ride, but I never get really wet)
After this, you should be back at HP with the sun setting and a few more hours left to explore HP once again during my personal favorite time to see it. It is really amazing looking at night.
IF you do not care about doing HP once again, you could head back to the Studios (about a 3-5 minute walk from IOA to Studios) to ride some things you missed or to catch the nighttime show again.
Overall, try not to go to Universal stressed out because you don't have a plan. The biggest tip I can give you is this:
Print out the park maps, read about all the rides, circle the ones you want to ride and then follow a path to reach them all. Both parks make a big circle around the water areas so simply ride the rides as you reach them.
Since you don't have express, I really don't suggest skipping rides you want to do simply because the wait is long. For example, if you skip MIB because the wait is to long, it will take awhile to get all the way back to the ride later in the day which will waste some time. If the line is really long, give the single rider line a chance. Take two kids and one adult through the single rider line, having the adult ride first. Then wait at the exit of the ride for the two kids to get back. Doing the single rider line can really cut back on the wait time.
As far as express, it is not needed. While it is nice to have, it is not needed and you should have no problems seeing everything you want. Just don't head back to the hotel for a nap in the afternoon! You will need all the time you can get, and the walk back to the car, the drive to the hotel, the nap, the drive and walk back to the park can EASILY waste 3 hours. Just stay at the parks all day, and you will have a lot of fun! Relax and just go with the flow. No need to stress about Universal...leave that for Disney trips.