It would be much easier to identify if you had a picture of the fruit. The leaves that one person recognized as zucchini leaves (which it is not because of the long vines) are more common in the C. moschata group of squash. The most common of which would probably be a butternut. Did you put any butternut squash in your compost?

That pot has 2 squash seedlings (too small to identify) and a tomato (bottom right of the pot) and I can't really see the leaves of the thing on the bottom left.

And the orchid is reminiscent of a Cattleya.

It has no fruit yet, unfortunately. Would have taken

The leaves of the inidentifiable plant are most likely to be a Loofah, since I remember composting loofah seeds.

However...the huge silver leaf thing...no fruit, no flower so really don't know