I purchased and planted this plant about 2 months ago from Walmart, where it was labeled as some kind of cucumber (can't remember the exact variety). It has large, broad leaves like a cucumber plant, but there are no signs of any tendrils or fruit developing and so far it has grown like a bush rather than a vine.
It also has very large 2-3" diameter flowers, much bigger than the pickling cucumber varieties I've grown in the past (they are all closed in this picture).
You are correct. It is not a cucumber. It's a squash. See how huge the flowers and leaves are? Cucumbers don't have flowers like that (they're small). Cucumber leaves look different, too (they're smaller with different texture).
Since it has a bush habit, I'm guessing it's a summer squash, but there are a few winter squashes with bush habits (e.g. Trivoli F1).
The leaves, however, are an unusual shape for a squash, but it's still a squash. I'm very curious what kind, and what species, though. It might be an interesting species. The leaves look similar to those of Chayote, but I think that vines.
This link shows a picture of a summer squash (unidentified variety) with leaves similar to yours. I figured yours was probably a bonnieplants.com plant, since you got it from Walmart. So, I searched for squash there and found this picture. I guess maybe that leaf shape isn't so rare (but I haven't seen it often myself). Your plant is probably C. pepo (maybe a Yellow Straightneck squash or something). It's normal to see lots of male flowers before you see any female ones. Just wait. (That's normal for cucumbers, too, though, except for some varieties.)
Well, all could be well, there are bush cucumbers with a non-vining habit, and it is fairly common for members of the squash and cucumber families to begin flowering with nothing but male flowers until the plant reaches a certain stage of maturity at which point the female fruit bearing flowers begin to appear. I'd say give it a week and you should see small fruits appearing.
