If you see a wire going to it, very likely electric.
Seriously, if engine is carbureted, mechanical fuel pump will be bolted to lower right side of engine. You'll see the supply hose from tank, and then another hose going up to your carburetor.
If engine is fuel injected, you'll probably see a cylinder, about 3-4 inches in diameter and 6-8 inches long on right front of engine. There, on top of it, you'll see a wire, a supply hose going to injector rail, and a hose for fuel return.
Also, if electric you'll hear the pump kick on briefly just as you turn key, first click, on to ignition