I recently started a new job. It's less than 2 months long but there's a chance for extension. I'm really glad I got it because I really needed money and it's in an field I want to get into. I was hired by a contractor who felt he needed assistance and I had met him a couple occasions. He knew I used to work at a company that uses the software we are using in this job. However, he seems to have overestimated my knowledge and experience with it, I don't believe I said anything misleading but he wanted to hear what he wanted.
I really want to do my best but given I am the first person he has trained and the time is so short, I'm looking for suggestions how to make the most out of the situation? Sometimes I find he speaks a lot about theory and at the end I'm not sure what actions I should do. Should I directly tell him that 2 months is not enough to learn complex systems and I should stick to simple tasks? I know all of this is a vague question but how long is a reasonable amount of time before one becomes productive at a new job? I heard it takes 4 months to learn a new job. With the rate things are going I'm expecting I won't even have access to all the accounts before the first week is up.