Going commercial..

I have a chance of going to school for free through my company who I work for, I'm seriously thinking of taking the 240 hr course in commercial refrigeration, I went through the residential school but this I think would be a huge step for me, I would have to sign a contract with the company I work for but not a problem being their very good to me as I am to them.
I know it's much different than residential but how difficult would it be for me?
Would be more money for me but more work..