You'll most likely get qualified on a few "B" vehicles (Iltis or Gelandewagen, LSVW and MLVW). Then depending on a whole bunch of factors, you'll be trained as a Coyote driver, gunner or surv op. Eventually you'll get trained in all three positions. After a bunch of years you'll most likely end up being a vehicle commander.
This is all assuming you're joining as an OR.