Hi BristolBarb
I did the AGW tour a couple of years ago (you'll have an amazing time) and don't worry, you'll have plenty of time at Universal. The trick is to do the Studio Tour when you first arrive - the queue looks huge but it moves really quickly. There are about half a dozen other large rides and several stage shows which repeat throughout the day but, as you are going after the end of the school holidays (as I did), the queues for these will be much quieter.
The park is on a hill side above the working studio and is smaller than you would think but a lot of fun. There is also a mall of shops and restaurants directly outside the park gates if you have time on your hands while waiting for your bus.
The Hollywood tour in the morning is also really great - take a tip from me and when you stop at the Farmer's Market, find the Italian Bakery at the back and try a bearclaw. Warning - your waistline won't thank me!
Have a fab holiday
Mandy