Looks like blueberry to me. We have a few bushes at our citadel.

Vaccinium Angustifolium?

Harvest time varies by region but summer is what I expect you mean.

You eat them. Right off the bush or make a pie or cobbler with them. They are delicious and good for your body. Growing your own food is another act of rebellion against the state. Anything that makes you more independent and strong is a win against tyrannical overlords.