With an avatar like that you'll always get help...
The reservoir is the fill for both the brakes and clutch and can be seen atop the drivers footbox in my photo. The line for the clutch is the upper connection on the bottle.
You must determine where the fluid went since the level got low-it's leaking at the masters, calipers, junction fittings or the clutch slave/master. Just adding fluid is not good because the clutch line probably pulled air. So the brakes and the clutch should both be bled. Good time to change to fresh fluid-every two seasons.
