I agree that it looks like some kind of squash plant.
I know you didn't ask but in your third photo there is a square pot - those look like chives.
JRsbugs said:A big pot will have to do, but watch to see how it grows. If it's cucumber and makes tendrils you might need to put canes in for it to grow up.
You will find out more when the small fruits form, cucumber will be elongated and spiky looking.