Let it go. They’re going to make really stupid choices. I drank AND smoked in high school. We all go through it. They need to be able to trust you and rely on you. They’re navigating the world and they need a safe harbor. Be that safe harbor. It’s more important than fighting over stupid behavior. Let them know you don’t approve - sure, but fighting over stupid stuff is just going to make you both bitter.
There’s a lot of virtue to the “Let them” theory of parenting. It’s their life. Drop out of school? Not what I would want, but as long as I’ve had my say, the decision is theirs to make. The mess will be theirs too, but that’s just life. Stop trying to control everyone and everything. Give yourself and everyone else a break and as long as it’s nothing harmful, let them. Don’t try to bend them to your will, and keep your opinions to yourself.
Start “home economics” school with them. Laundry, cleaning, cooking, how to change a diaper, comfort a baby, soothe a toddler, what's involved in caring for pets, budgeting for food, keeping track of maintenance schedules for humans, pets, cars and machines. Engage with guests, be a good host, etc. Know when and how to tell someone to GTFO of the house (racist or misogynistic speech, etc.) Every kid needs to learn the art and science of home management. Look for and point out examples in books and movies of good home science skills.
Maria Shriver has lots of great parenting advice. One of my favorites is (paraphrased): “Children need what you need: to be seen, to be talked to, to feel safe and loved.”
You can get into big trouble (with school and the law) even by fake / joke threats of violence (bomb threat, etc.)
No jokes or pranks that have anything to do with violence.
Favorite bible verse: Psalm 143:8 “Let the morning bring me word of your unfailing love, for I have placed my trust in you. Show me the way I should go, for to you I entrust my life.”
Eat at a local restaurant tonight. Get the cream sauce. Have a cold pint at 4 o’clock in a mostly empty bar. Go somewhere you’ve never been. Listen to someone you think may have nothing in common with you. Order the steak rare. Eat an oyster. Have a Negroni. Have two. Be open to a world where you may not understand or agree with the person next to you, but have a drink with them anyways. Eat slowly. Tip your server. Check in on your friends. Check in on yourself. Enjoy the ride." - Anthony Bourdain