if you want to beat rush hour and the crowds at the park, leave early and be at the parking garage around 7:45.
if you do so, you should be about the 4th or 5th car in line.
the garage opens up at 8.
if you wait until 8:30 to arrive at the garage, you will have a wait to enter it.
if you park your car at 8 and at the turnstile around 8:20ish, your wait for entering the park will be short.
do ioa first as they usually open the gate around 8:30ish.
not all rides will be open but you can do repeat rides for hulk, spidey, doom easily.
by 9, the rest of the rides will be open.
leave that park and go to the studios after lunch. you might have some lines there but not too bad.
as long as there is no
hhn event for the night you are there in the park in the daytime, you should be fine and be able to do the parks with limited waits.
on the nights hhn is happening, crowds tend to hit the parks around 2ish.
hope you have a great time there.
follow the directions metro gave you and you won't get lost.