Some people will be shocked that I advise teens to lie to their parents. Deal with it. I'm realistic; most teenagers are already lying to their parents about something, and chances are there will be some skeleton in their closets for the rest of their lives where their parents are concerned. This is how life is.
Life is also, for teens, dealing with mind-altering substances. We all did DARE. We all know it doesn't work. A friend of mine takes perverse pleasure in the fact that she won a prize for her essay for DARE just months before beginning a marijuana habit that's with her to this day.
We all know that teens in small towns get bored and go to parties and get tanked, or smoke weed, or occasionally go for something more dangerous--acid, or one of those nasties. I haven't done them, mostly because they scare me, serious phobia-type. Losing control is a big panic button for me. However, most of my friends have partied, some half-heartedly, some seriously. Getting ahold of alchol is a lot easier than it should be, and it's just the accepted thing to do, along with smoking a bowl. I know kids who've managed to keep their pot-smoking from interfering with their lives. I also know kids who haven't. Be smart about it, if you're going to use drugs. Know what it is, what it does, and how to deal with it.
As far as performing magic while drunk or high: how stupid can you get? Do you just want to attach a big flashing neon sign to your forehead that says, "All Psychic Nasties, Come and Get a Big, Tasty Treat!"? There's a place in the woods up here called Sixpack where teens go to get drunk. People have tired various stupid shit there over the years, enough of it magical so that I won't go near the place--it's got Psychic Ickies written all over it. You get within a quarter-mile and it feels like there's an iron band crushing your chest. Not fun. So, stay sober while you're in the circle. It's one thing to have a sip of ritual wine. It's quite another to get smashed and then try to control the forces of nature.
I'm not going to judge drugs and alcohol in and of themselves. That's not for me to decide. However, I will tell you that these things do impair your judgment, so if you're going to use them, have some intelligence.