Certain stores have discounts for seniors wherein you can get 20 to 30 % off on certain days.
So if you go with your parents or grandparents, then try Shoppers Drug Mart on Thursdays for 20 % discount on non-sale items.. They must have an optimum card to get the discount.
Value Village has 30% off for seniors on Tuesdays. Salvation Army stores have a daily 10 % discount for seniors.
Other stores, such as Rexall and Pharmasave, have similar discounts for seniors, but check with them as to when they have them.
At the same time, there are discounts for students at stores, and other services, museums, etc... so bring your student ID with you and ask if they have any for students.
Good luck.