If you're looking for an "L" button on the Wii Remote, you won't find one. The Wii Remote's button layout is distinct from traditional controllers, and this confuses many players—especially when games prompt for "L" or "R" inputs.
The "L" button is on the Nunchuk attachment. The Nunchuk plugs into the expansion port at the bottom of the Wii Remote and features:
If you're using a Classic Controller or Classic Controller Pro, those do have proper L and R shoulder buttons (plus ZL/ZR triggers), mapped to the positions you'd expect from a traditional gamepad.
So when a Wii game asks you to press "L," reach for the Nunchuk's Z button—or switch to a Classic Controller for a more familiar layout.