Having it on "PARKING"
What would cause the 1995 Nissan Pathfinder not to go in forward or reverse?
no it will cause u 2 go > slowly >=forward
could be either transmission shift linkage not engaging reverse ( stops at neutral ) worn joint connectors sometimes cause this. or reverse clutches or gears bad inside transmission.
The transmission is broken. Take it to a shop.
If this is an automatic transmission, more than likely the transmission is on it's way to the junkyard. Usually failing transmissions lose reverse first, then the higher forward gears - last will be the lowest forward gears.
Is there park and nurtural?
Burnt forward clutches/ The forward cluth pack is stuck/welded together.... You need a overhaul...!
Linkage needs adjustment?
I mean this seriously: Where you can get a good used replacement. There is nothing external that can be the cause, it has had a serious internal failure and either needs overhaul or replacement
The emergency brake cable is probably seized and the emergency brake is not releasing.
Inspect your brake pads. I would suspect they are worn out.
* cause it needs to be put in drive to go forward