1996 aurora transmission trouble!!!

[aurora fan]

i'm hoping to purchase a 96 olds aurora and i'm all gung ho for it... except the tranny, the man who owns the car (and i witnessed this) said that the car will not goto to first if you put it into drive, you have to manualy shift it to first then on up through the gears and drive is fourth gear on that system so it works but i would realy like to have the security of a fully functional transmisson if i'm going to buy this car, it seems to me that when its shifted to drive its either staying in neutral or shifting to fourth not entirely sure.

also when trying to cause th car to downshift by flooring it its reluctant then finaly it spasms almost puts nose to gravel then jumps to the lower gear

ANY help on what i can do to fix this would be extremely appreciated
thank you