The engine revs and car doesn't move.
No. The engine starts the car.
If your car still starts then you probably need some transmission fluid. If after that it still doesnt work your transmission probably droped and you'll need a new one. also try pushing on the clutch
It needs a rebuild.
The transmission is not engaging. Either the transmission control linkage is somehow disconnected or the transmission is not working. This could be due to excessively low fluid, the controller is not working, or a mechanical failure in the transmission.
what is the problem when the car will not go in drive or reverse? and the transmission fluid is still full
You have transmission problems, see your local transmission shop.
well there is a go cart
No
Inside the transmission, above the transmission pan.
The transmission needs fluid to propel the car. If there's no fluid, you're going nowhere. Fill it up, and find the source of the leak. It could be a transmission seal, or maybe it's as simple as a damaged line from the rad. Don't try to move the vehicle at all until the transmission is full of fluid. You could burn out the transmission, causing a very costly repair.
What type of transmission do you have Maunal or Automatic? If it is a manual transmission then possibly the clutch is worn. If it is an Automatic, then possibly the fluid is too low or may just need service. Check underneath the car to see if the fluid had been leaking. Do you recall a leak underneath?
Should be a plug at the side of the transmission fill to oil starts coming out of this plug