Is unpaid training legal?

I started a job at a gas station/convenience store in which they say training is unpaid and lasts as long as it takes for you to learn everything and be able to be left alone. I trained for 4 or 5 days. I was told that I would be given a 1095 at the end of the year and pay is minimum wage. The owner still has not given me proof of employment that i need for social services after 2 months and my food stamps got cut off because of this. I get paid in cash. I am asked to go shopping for the store, drop deposits at the bank, and the schedule is rarely done and lots of times i only find out if i work the night before or the same day (depending on if one of our other employees is able to work since she has another job). The manager says he never fires anyone.... he just takes them off the schedule more and more days until they quit or find another job on their own.... even if he only gives them one shift a week. is this legal at all? I am a single mother of 4 kids and can't take much more of this. I have heard that other employees have quit and went to the dept. of labor about this but never get any results. can anyone point me in the right direction on where to go from here? I am in virginia.