Air traffic will be able to report either QNH or QFE and the choice is yours as to which you will use.
Quite simply, the aerodrome QNH would show you the aerodrome elevation (amsl) on the altimeter when sat on the runway, whereas when set to aerodrome QFE the altimeter will read 0 feet.
You therefore have a choice of using aerodrome QNH or aerodrome QFE but more importantly remember which one you have actually set. This will hopefully be repeated over and over during your training so I wouldn't be overly concerned.
IFR flights normally use aerodrome QNH and the pilots factor the aerodrome elevation into their calculations whereas most VFR flights tend to use aerodrome QFE within the vicinity of the aerodrome, which will show the height above the aerodrome.
Hope this helps