Why won't my 93 kawasaki ninja start?

[Tyler D]

1993 model. 7600 miles. 250cc. I got it a couple days ago and the guy told me he just got it tuned up and changed the oil. it was running fine, but when i wanted to start it, i would have to engage the choke, otherwise it would start and die and the oil light would come on(is this normal?). Well this morning i started it with the choke, drove it, and dropped it turning off a street. it broke the turn signal and i think the front wheel is a lil off center. i picked it up and drove it home. I just tried to start it up a minute ago with the choke fully engaged, the bike cranks and sounds like it wants to start, but then it gets weak and starts clicking. its very cold here btw