Looking in the engine bay it's on the top left side of the motor under the sheet metal for the engine cooling tin.
You have to take the tin off in order to access the oil cooler. The cooling air for the cylinders also routes some of the air to the oil cooler. I comes _out_ the front of the tin right on top of the #3 exhaust pipe.
NO
A 1974 Volkswagen Beetle takes 2. 5 liters of oil. The weight of the oil should be 15W30. When the oil is changed, the oil filter should also be changed.
The 1974 VW Super Beetle engine oil capacity is 3.5 quarts. Three quarts of oil will be in the engine and one half quart of oil will be in the oil filter.
2.5 litres.
2.5 litres
Stock motors used 30w.
At the auto parts store with the name of a different car written on it. 1974 Beetles don't have oil filters, they have oil strainers that are in the crankcase at the bottom.
Two and a half quarts.
oil and a sump gasket
There isn't an external oil filter on a STOCK Beetle. There is a screen that is suggested to be cleaned/replaced. There is a plate that the drain plug is screwed into that has 8 or so small bolts that holds it in. Just order a "Beetle Oil filter Kit" and it will have it all included. If you have an aftermarket external filter then it will usually take a Pennzoil PZ1 or a Fram PH8A filter.
That should be the crankcase breather tube.
Your transmission does use lube oil. It takes a thicker oil like 75w90 or 90w140 and NOT automatic transmission fluid.