It's probably running at 48MHz (if you are using the standard Microchip code) but can be programmed in software. Almost all modern micros use a PLL (google it) to multiply the crystal (or internal oscillator ) frequency up to a suitable speed for the core. This is because high frequency external oscillators use lots of power and can have many other problems too.
Approximately 40 years as an electronic engineer - you either learn stuff or find something else to do.
It's much easier now to get information than it was when I started. Follow newsgroups, join a few forums like E14, read on-line magazines, design your own stuff (and do it properly, start with the data sheets and the app notes from the chip makers, not with a spoon-feed from AdaFruit or similar).
Follow newsgroups, join a few forums like E14, read on-line magazines, design your own stuff (and do it properly, start with the data sheets and the app notes from the chip makers
AND internet search engines are your friend.
I always find that doing your own research leads to better understanding and better retention of the information.
You may also discover some other very interesting/fun uses or applications while searching.
