Crookneck squash can be cooked just like plain, yellow straightneck squash and/or zucchini.
One of the ways we enjoy any of these is to slice them in about 1/4-inch slices, dip them in beaten egg, then in seasoned bread crumbs and fry the breaded slices in a shallow bit of oil. Pretty tasty.
Another way is to cut them in big cubes, like thick slices then cut the slices into quarters. Put them in a pan with some coarsely chopped onions and a bit of water, not too much, and simmer/steam them. Season with salt and pepper and serve.
There are plenty more ways and, as Carol suggested, searching for ideas via the Internet will give you more ideas than you'll have time to prepare.
"As a girl I had zero interest in the stove." - Julia Child
This is real inspiration. Look what Julia became!