There's nothing wrong with drugs & alcohol as long as it's done in moderation. For instance, I'm under-age and of course I've touched alcohol, what British teenager in the 21st century hasn't? Unlike the majority of people I know where I live, me and my friends don't get wrecked every weekend. Two of them have gone straight edge, meaning they don't touch drugs or alcohol!
Personally I've never touched drugs but about 95% of the people I know have, a few of the people I grew up with are now on drugs on a regular basis, that doesn't change my opinion of them. They're still the same people I knew they just harm their bodies in an unnatural way, thing is I won't judge them for it. It's their choice at the end of the day!
I've been lucky in my life, I have never been pressurised into taking drugs or touching alcohol or into smoking. If I try something it's my choice and no-one elses.