Try not to expect anything in return. Though it would be nice if the apology immediately fixed everything, that is unlikely to happen. It’s possible that your parents may not know the best way to respond to your apology. The words you use are less important than speaking genuinely. Another part of apologizing is forgiving yourself.
Be honest in your response to their request. If they seem to have an unreasonably long list of things for you to do, tell them (without whining) that you think you would have trouble being successful at meeting their expectations. Offer a compromise instead.
Remember that you will eventually have your own home and you can live the way that you want to live later. Even if it seems like an eternity before you move out of your parents’ house, the time will pass and you will be able to move on eventually.
In the case of something like substance abuse, you may need professional help to fight an addiction. If there is a particular friend who leads you to make bad decisions, it may be time to move on or take a break from that friendship.
It’s important that you understand what the rules are, why the rules are in place, and how to follow them. An open dialogue with your parents about these can help you make better decisions in the future.
Putting yourself in their shoes and thinking about how you would want someone to apologize to you can help you know what will heal the wounds.