Chris;
A mentor is a great opportunity
Man O man I would love to have an opportunity like that, its a "OPPORTUNITY" Jump on it, as long as your not losing money whats the worst case scenario
If It was me this is how I would approach it.
1st We need to have an up front understanding, so later there is no misunderstanding. In writing if possible (CYA)
2nd, question to ask your self and maybe him, does he normally have inexperienced Project Managers run his projects, Whats in it for him. (CYA)
Then one needs to understand to make money for self, you need to make money for others. How are you helping him make money.
whats his expectations
Who's making the schedule
How are you getting compensated and when
Meet with him everyday if possible even if its for a quick coffee, get to know him personally, create at a relationship, ask questions, then listen.
Do more then is expected and ask for nothing in return, you will get compensated for that later (Maybe)
Get your hands on anything you can about Project management and read it. lots of info on the web.
Read How to win friend and influence people, BY Dale Carnegie and Think and go rich by Napoleon Hill
Don't be afraid to speak with and ask question of the trades, suppliers, city officials and whom ever is involved, they have been there and done that in there area of expertise, most of the time they know the best way to get it done, just ask, What do you think is the best way, then take notes, you get them on your side they might do a little more if asked.
The only thing I can guarantee is, if you don't try, nothing will happen
This might lead to some cool stuff, one never knows.
Good luck