Set up automatic payments so they are initiated on your end, so that you send out money to the bill/ company you’re paying instead of giving them access to take money out of your account.
Start a yearly “review” right before school year. Raise allowance as appropriate. If they want more money, they’ll have to take on more responsibilities.
Start saving for retirement with your very first paycheck. Put away the MAX, you’ll never miss it. If the company doesn’t offer 401k then we’ll open a Roth IRA.
Beware that when you’re first exposed to a new thing: a car, a college tour, house, etc. you will feel AMAZING and totally seduced by the shiny newness. Be cool. Remember that glitters is not gold. Things don’t need to be perfect and even if the house is it doesn’t mean life will be.
I once asked my mom if my grandmother (her mother in law) was rich. Her reply: “No, but she likes to think she is.” I think she meant my grandmother spent money like she had plenty of it when she really did not. Can relate. I hope you do better!