Well they're vegetables so yea. I eat cucumbers plain, zucchini fried or steamed and squash is more a broad term. You get loads of different varieties just to confuse you more. But really just try them to find out for yourself. Or you know... try Google.
Hey Tom! Sounds like you're new - or hoping you are and not just attempting to be sly :)
Anyway - eating whole real food is what you're after.. and yes, squash fit into that category.
Some good resources: Whole 9/Whole 30 breaks things down nicely. Check out the blogs by Paul Jaminet, Mark Sisson, Robb Wolf, et al. Primal Blueprint is popular. And yes - you can literally google "paleo vegetables" and loads of results will come back :)
And to answer your question: