This is a spaghetti squash. A squash this size will feed a family of four or five. It is called spaghetti squash because you rake the flesh out with a fork and it comes out in strands somewhat like spaghetti.
You serve it like you would pasta. Drizzle with olive oil and sprinkle with salt and pepper and maybe a little Parmesan cheese. You can also top it with a sauce like Alfredo or marinara.
Preheat your oven to 375 degrees Fahrenheit/190 Celsius.
You will need a pan large enough to lay the squash in.
You will also need a knife, a large spoon, and a fork.
A towel is nice, but not necessary. 
1 spaghetti squash
Wash your squash off and pierce the hard skin a few times with a knife.
Lay in the pan and put in the oven.
Bake for one hour and poke with knife to see if it is tender. If the knife goes in fairly easy, it is ready. 
Take out and let it rest a few minutes.
With the knife, slice it in half lengthwise.
With the spoon, scoop out the seeds and spongy stuff.
You might want to hold a towel against outside of the squash so it’s not so hot.
Rake the fork down the pulp and it will come out in strands.

Serve with sauce of your choosing.

The seeds can be roasted like pumpkin seeds or dried and saved for future planting.