Yes, you CAN use the seeds from vegetables and fruits you buy at the grocery. It doesn’t work for all produce, but many can be used.
Start with a fully developed, ripe fruit or vegetable that you’d like to grow. Baby vegetables, like baby zucchini and squash will not work because they did not fully develop.
The trick is to fool the seeds into the season.
Remove the seeds. Wash and dry the seeds with plain room temp water. Put the seeds in a ziplock and freeze for 2 days. Put on the counter for 2 days. Put them back in the freezer for two days. Thaw, and they’re ready to use.
The freezing/thawing tricks the seeds into “thinking” they’ve been through winter and spring.