My Great Uncle was a RN Commando as a Medic and even handed out sea sickness pills to Ian Smith (Rhodesian Prime Minister) in his time as well as seeing people been eaten by cannibals in Borneo.
His skills gained him a hatred of ALL things non white and language that would make a dock yard worker blush. After his 22 he worked in a type writer factory then a window extrusion factory and collected love birds.
In conclusion what career you will "GAIN" will unlikely to be anything to do with what you learn, however your state of mind will definitely be changed for the better or not is entirely up to you.
Seeing as its unlikely you are going to be joining over Christmas and New Year, the information you are looking for is perhaps best sought from a recruitment office when they open again. There are 1001 careers you could do and so you need to think about what you like or want to do.