I’ll take a shot.
IPC is Industrial Production Certificate. That’s the monopoly money in the set you use to purchase units. Units are built in territories with an
IC Industrial Complex
KJF is Kill Japan First a strategy where the Allies attempt to take Japan out of the game before taking out Germany
KGF is Kill Germany First
SBR is Strategic Bombing Run
Most of the others are just short hand for units or territories.
INF– Infantry
ART or RTL– Artillery
ARM– Tanks or Armor (as called in classic)
SS or SUB– Submarines
TRN–Transport
FIG or FTR –Fighter
DD or DES – Destroyer
BB – Battleship
BOM or BMR- Bomber
AA – Anti-Aircraft
WUS–Western United States, KAR-- Karelia, CAU-- Caucauses and so on.
As you play some games and get familiar with the rules it will be second nature to you before you know it. Especially if you start playing by forum.