Living at home while enrolled in post secondary school or training can save money on several items, although the most important one of these is rent.
Living at home allows you to save money on rent (as long as you do not have to pay rent at home). This is one of the most important expenses that you will have when you first move out. Moreover, people would generally also save on bills, as these are likely to be paid by your parents. Finally, you are also likely to save money on food if your parents pay for it.