Renovating Old Brownstone Apartment

There’s a elderly lady who lives in the brownstone next door to me. She offered for me to move into the apartment inside her brownstone for less than half the market rent. The catch is the apartment is terribly dated although livable. The brownstone was never really changed from a one family except for the seperate kitchens on each floor, that said the bathroom and kitchen is only accesible from outside the main part of the apartment. She said I was free to renovate the apartment and she would take it out of my rent which sounds good. The problem is I’m really young and I don’t even know how to begin doing the work or how much it would cost. I’d like to start with restoring the wood floors, a portion of the apartment has the wood floors in tact, a portion has linolium and another portion has carpet. Has anyone ever done something like this? How much should I expect to pay to sand and polish the floors per sq. ft? Also, I’d like to update the kitchen cabinets and the tile in the bathroom and kitchen. I’m sure this is a broad question but I’d like to know what I may be getting myself into. I can’t afford a contractor and I don’t really think its necessary. Any suggestions would be very helpful. Thanks