opening used car lot all known cost?

I am opening a lot in my rural community, I am a nursing student but I want something else to do. and possibly go on with later in my life.

beyond the physical lot..
what all kinds of things am I looking to be out as far as things you business gurus know get slapped in the face down the road with something you didnt know you had to have to operate you facility. thanks alot guys and I am young and green, I have never taken this size risk and forums have always been the best place to find any kind of specific information

all I know so far is RENT or LEASE so Im not out 100k to build and own my own lot, so I have found a few options in great locations.

just give me your personal pointers.

they are GREATLY APPRECIATED and if nothing else just say hey thanks!