Can I get an Uber from there?

there is no network or wifi anywhere within or near the park - I would suggest depending on Uber or Lyft.

Its really off the beaten path and there is no service. I rented s car and printed tickets at home. E ticket wont load.

Taking cab is not advisable. Better book the bus. Also a note for others driving, there is no wifi and parking should be booked online. Better book the parking BEFORE going or on your way there.

You can't. The only way out is if you have your own vehicle or if plan to use the buses offered by the MGMT. P.s. pre book the tickets for these buses since you are not guaranteed a spot .