AutoEvolution

Im looking at buying a 240sx from a guy but one of the things wrong wth it is when you go to put it in first gear if you push the shifter all the way to the left side and go up there is nothing there and if you pull it down like if you were going into second gear there is nothing there either. if you move it over to the right a bit it still goes up into first and down into second and all the way through the rest of the gears it just makes it hard to find the gears. What could the problem be? Is the shifter just not lined up correctly or somethig. Im new to all this five speed stuff because ive always driven trucks so any help is greatly appreciated.

Thanks,
Larry