"Cadete" (at least in Argentina) is the (poor) guy/girl who does whatever needs to be done in an office and especially out of it. For example, he/she usually delivers or picks up envelopes, parcels, etc. to clients or other companies, pays bills, goes to the bank, picks up clients' payments, buys stuff; he/she might also have to run personal errands for the high bosses (from dry-cleaning to car-washing...) or even serving coffee or taking photocopies. (I know all this because this was my firs job some 15 years ago!!! :) The English term for this is "Gofer," derived from "go for," because the person "goes for" this and "goes for" that. The other suggestions given like assistant or junior sound rather formal to me and seem to denote some rank (though very low) and higher responsibility; they sound like desk jobs or "inside-the-office" jobs. A "cadete" generally spends more time on the street running errands than inside the office. Hope it helps!!