Look around and find the exit(s).
I attempt to find a table (better than a booth as it is easier to move, and I'm just chubby enough to make a booth awkward) where I have a view of the primary entry and cashier if one exists. I prefer a location where my back is covered, but it's not always available.
In a theatre, the entry is ALWAYS to the rear. One remains flexible and observant.
Life has no guarantees aside from God; and those guarantees do not include long life and total safety on Earth. If you want a guarantee, buy a toaster.