You did not specify where you are coming from so:
Coming from the Oryx Roundabout (roundabout with an Oryx statue on top) Just go straight down the following:
1. TV Roundabout; then
2. Burgerking Roundabout (or R/A near Markhiya Petrol Station); then
3. Go through the underpass of the Immigration R/A ; then
4. Sloping roundabout; then

Now you have 2 options
1. take a left on the roundabout after the sloping roundabout. The QF entrance (gate 3) is to the right of the roundabout after that

2. go straight on the roundabout after the sloping roundabout. Then make a U-turn on the next roundabout. Go past gate 1 and after that you will find an access road going right. Follow that access road to Gate 2.

BTW Corne's school is the first row of buildings you will see at 11 o'clock position from the sloping roundabout....