You can get a harvest from store bought garlic
I bought a few bulbs over the winter to plant as an experiment. Towards the beginning of spring, while it was still cold, I planted them in small cups.
Take apart the bulbs into individual cloves, and plant the largest ones pointy side up. Add occasional water and let them grow.
I don’t remember when I planted them in outdoor containers, but it doesn’t matter. They tolerate the cold weather just fine. It seems most people plant them in the fall to harvest the following summer. I didn’t do it that way.
The cloves I harvested were small, but the ones I bought were small too. They are hanging up to dry.