There are a couple restrauants in Luray. It is just a small town. Not sure if they have any rental cars at the airport. It is probably about 2-3 miles from the ariport to the caverns. They are both on the west side of town. There are a couple of hotels/motels in town also.
W45 website states:
"Free courtesy transportation is provided to and from Luray Caverns, Caverns Country Club and affiliated attractions, restaurants and motels, all located one mile from the airport. Rental cars can be arranged in advance."
Luray is a small town with nice people. The caverns were a lot of fun to visit for me, I'm sure you will feel the same. The town of Luray is nearby where there are some mom and pop food shops, also nearby there is a Burger King I think.