First, you don't realize how lucky you are: there are thousands of posts across the web about people complaining that their employers give them no training at all and you're basically getting 2 years of "apprenticeship" training right off the bat.

Make the most of it. It will never happen again! This is old-skool training and more companies should be doing it.

Second, your manager needs to know ASAP that you can't finish. Whatever the consequences of not finishing are, they will be much worse if it's a surprise to him at the deadline. Just walk into his office and TELL HIM. Don't sugarcoat it, just explain what's going on. I've had to deal with exactly this situation in the past month. It happens, we deal with it.

People not being able to do the work isn't new to any experienced manager, he'll figure something out: that's his job. Yours is to keep him up to date.

How bad is it in real life? In real life, not finishing a project on time can be the end of a company. I sincerely doubt you are doing anything that crucial, but you asked. Things get a lot more important when people are paying you to do them We all do shit that we "just don't enjoy" but we're paid to do them well anyway. It's not like they expect you to do this for the rest of your time there.

Don't switch jobs unless you are otherwise a fantastic candidate and you can come up with an amazing excuse in the interview for why you only lasted 6 months. And it had better be along the lines of "the boss beat me daily with a stick because I wouldn't wash his car." No, I'm not kidding.

What college did you go to that you got "do-overs?" Friggin' lucky. If we were late on an assignment, it was an automatic 50% off and got worse with each passing day (sometimes hourly).

This isn't a rant, and I'm not picking on you. I read inexperience in your post and I think you have a great opportunity you're about to throw away. Think carefully before you do.