Depends on when you get the first freeze/ frost in your area. You can successfully grow Cauliflower in the late summer/ autumn. Cauliflower doesn't do well in hot summer weather, but will grow in cool weather, you just need to get it big enough to head up before serious freezing. Broccoli too.
You may have time to grow the the Zucchini and Cucumber before cold weather, but you may run out of time for much production. But you have the seeds, you may as well plant a few if you have room, I would try. Plant a few seeds now, maybe you will get something.
When it gets cooler you can easily grow Radishes. You could try Carrots, try a shorter variety if you are just starting a garden. You can grow Lettuce when it is cooler, but I like spring lettuce better.
Q