I have a 1991 nissan stanza, nice car, but when i put it in first gear it will move apx. 3 feet then lock up, it doesn't do this in reverse, what is the problem? thanks

Is the parking brake on? I don't know, man. I guess you'll just have to drive around in reverse!

Not enough information given.
Try this to narrow down the problem, if you can.

Jack and support both rear wheels off the ground with the front wheels securely chocked to stop any possibility of the car moving. Put the car in NEUTRAL. Make sure that the parking brake handle is to the full OFF position. See if each of the rear wheels turns freely in each direction. I suspect that you may have a stuck wheel cylinder at one rear wheel that allows easier rotation in the reverse direction as the shoes would tend to "unwrap" from the drum in that direction.