I was in the same boat earlier this year - yes, rides will shut down and most shops at 9pm close but there are still lights and sounds on (Galaxy's Edge is particularly cool and eerie at dark with most people gone). I did a quick lap around the park waiting for my reservation to start.
After you're done at Oga's cast members will direct you towards the main entrance to leave. Something to keep in mind is if you're planning on using a Disney bus to get back to a hotel they stop running pretty soon after park close. I'm not sure what the Skyliner schedule is.