The length of your stick depends on what position you play. Goalies, defensemen, and attackmen/middies all need different stick lengths to help them play their positions to the best of their ability.
A shorter shaft is best for attackmen and middies, usually around 30 inches. A complete stick (meaning the combined length of your head and shaft) for these more offense-focused positions usually falls within the 40-42-inch range.
Longpoles are usually reserved for defensemen and long-stick middies (LSMs). The combined length for a longpole stick is usually between 52-72 inches, with an average shaft length of 60 inches.
Goalies have the most freedom here, with some preferring shorter sticks closer to the length that a middie might use, while others could prefer a 72-inch stick that resembles a defenseman longpole.