QX-C = Qualifying Cross Country
As part of either course you need to do an extended flight on your own, which is checked and certified.
For PPL one cross-country flight of at least 270 km (150 NM), during which full stop landings at two aerodromes different from the aerodrome of departure.
For NPPL: one cross country of at least 185km (100 nm) in the course of which full stop landings at two aerodromes other than the aerodrome of departure.
IF will stand for Instrument Flying. On either course, you will only be qualified for flying in visual conditions (ie - you can see out the window). Just in case you ever go into cloud by mistake, there is a small amount of instrument only flying in the courses, enough for you to make a 180deg turn to get out of cloud so you can see again.
You can find the NPPL syllabus
here.
The PPL one is much harder to read, and is changing from JAR to EASA, but nothing fundamental is changing as far as you would be concerned. The old JAR one can be downloaded from
here under JAR-FCL 1.