I think that is a question best posed to the school.
Some people are put in Job Corps under Court order, I think! So, if that was part of some probationary plan, and you fail to complete it, there would be consequences, possibly to include incarceration. If Job Corps is so bad that you'd rather be incarcerated, that's pretty bad!
If there are specific problems with the facility you are at, are there ways to address them? Can you talk to a counselor or someone within the school? Getting a free trade education can be very beneficial!
Why do you want to quit? Homesickness? That's common! Part of the idea of the program is to get you out of the environment you were in, so you can focus on learning!
If you were simply selected for the program based on income level, and no other factors play into it, then, maybe. But, if you are a minor, I think there might be a parental involvement in that decision. If you are in a foster care program, they might become involved.
But here's the thing!!!! I look back on my first days in new schools, new jobs, etc and I ALWAYS wanted to quit. I didn't know anyone, they were all "different" than me, I didn't fit in, I didn't like it, it was the wrong job for me, etc etc etc!! But, I forced myself to stick it out. Give it two months -see where it took me and then go from there. You really don't want to start on a path of "quitting" every time something is a little uncomfortable. Quitters don't get ahead.
Now, I know about some of the Job Corps sites, and how they can be pretty rough. If you are PHYSICALLY in DANGER, that is a whole different question.
I think the important thing here is to first try to make it work for you! Then, think through the potential benefits of the program, and consequences of leaving, and be willing to accept individual responsibility for your decision.
I hope this helps, and ask if you have more questions!