Hiya, Kathleen!
Oh, what an exciting time to be visiting
Disney's Hollywood Studios. Since I'll be there for the big opening day of the much awaited, long anticipated
Toy Story Land, I've got my desk laid out with spread sheets that give me park timex, extra magic hours information, and an estimation of how long I can wait in line for any one attraction without someone in my party of 10 needing a restroom break. This is a big deal in my house.
What I can tell you is that the
theme park hours for Disney's Hollywood Studios on opening day are expected to be 8 AM until 11 PM. That would be for ALL guests - not just those staying at a Walt Disney World resort hotel. Now, I don't know if there will be any sort of fanfare that day, or special dedication, or anything that would bring a whole other level of crowd beyond what the opening day is already going to bring, but I would say if you could get to the theme park at least an hour before park opening, that would at least get you a jump on people who anticipate arriving at park opening.
Having said that, there are Disney super fans (yep, I'm raising my hand) who may line up much earlier. The parking lot can be accessed very early in the morning, and I would anticipate that for a momentous occasion such as this, the parking lot would begin to fill up by 6 in the morning. If you are using resort transportation, which generally starts running at least an hour before, try to be among the first group of people to head on over.
Have fun!