I'm in a different climate than you, so my answers my not be all that accurate.

Your zucchini got huge. Generally when that happens, the plant will often not produce much more. If you want continuous production, you should pink them when they are still small.

The Hubbard never produced. It probably is not well suited for your climate. It originally came from New England.

If I'm reading it correctly, you had 1 Spaghetti Squash vine which produced 3 fruit. That's about average for me. Some squash will only produce 1 fruit per vine.

The pumpkin plant has 2 pumpkins. That's a good thing, isn't it? If the description on the seed package or catalog said that the pumpkins were supposed to be quite large, maybe the cultivar isn't well suited to your climate. If you want huge pumpkins, you often have to start the plants very early in greenhouses and constantly fertilize during the growing season.

I don't see where you have "gone wrong" other than letting the summer squash get too large. Of course there is hope for further production if the plant is still alive. Many squash don't even start making female blossoms until the summer starts to cool down. Depending upon how much time you have before the first killing frost, you may be surprised.

Some general recommendations for squash:
~ No expectations. You'll generally only be disappointed.
~ You may want to start a trial garden each year. Just a corner out of the way somewhere. Either in the ground or in large pots, plant 10 seeds of each of several cultivars until you find one that grows well for you.
~ Find out what your neighbors are growing well, how they grow it, and do likewise.
~ Squash are heavy feeders. I have found that they appreciate periodic side dressing of urea and fish emulsion. Miracle Gro would also work.
~ Squash use a lot of water. If the leaves wilt, then water them.
~ If disease and bugs are a problem, then spray with a general purpose fruit spray, early morning and evening only, when the flowers are closed and the bees are gone.

Good luck.