I'm really glad you had the courage to ask this question - a surprising number of students find themselves in this quandary. My feeling is and I'm hardly alone on this, that most people grow and learn from their mistakes. And also that the teen years are when a disproportionate number of them occur. Young people don't always make the best choices, and peer pressure certainly complicates matters. If you've done something wrong (and not something criminal, harmful or egregious), it's unfortunate this may become a part of your permanent school record. But it need not define you.
Your first stop in getting the specific answer to your question is to speak with your school guidance counselor. Over the years I've learned that some high schools don't make mention of an in-school suspension on the official transcript. Fortunately, some won't even mention a full-out suspension believing it's unfair to penalize a student for a minor infraction with disclosure on a college application. However, this varies school by school. It may depend on official policy and/or the nature of your offense. It may reflect how school staff feel about your circumstances - so this can be a very idiosyncratic thing. You'll have to rely on your guidance counselor for what you should do with this section. Hopefully you are one of the lucky few who may not have to report the disciplinary action to college.
If you do, all is not lost. It's critical you provide an explanation about what happened and most importantly, focus on how you've moved on, matured and what you've learned. Alcohol and drug related incidents are not uncommon and won't necessarily disqualify you. Again, your best bet is to work closely with your guidance counselor on how to craft your response. And what kind of detail to get into. It's HOW you frame your response that will determine whether the admissions committee can see past your suspension. Humility, self-awareness and honesty are critical here. If this was a one-time event, your guidance counselor should reinforce your explanation in their official communication with the colleges, and provide evidence of your otherwise all around terrific-ness.
Back in the day, one or two students brought pot brownies to my school. I'm surprised to hear they're still the thing, though I by no means condone pot brownies nor bringing them to school. My point is, some offenses we can all relate to. If Ferris Bueller went to school today, he'd be expelled in a hot minute. But almost 30 years after "Ferris Buellers Day Off" first hit the theater, this John Hughes movie has become a cult classic. We love the disobedience, the foolishness, the shenanigans, the caricatures; it's a classic teenage rebellion flick. As charming as Ferris was, it's unlikely the admissions committee will be amused by whatever it is you are guilty of. But chances are, they'll understand. And not want you doomed by your youthful insensibility. They know the path to becoming a grown-up can take a slight detour. With any luck - depending on how eloquently you make your case - you might just impress them with who you've become, and where you're headed! Sometimes people need to fail, to succeed. And ironically - until just recently - overcoming failure was a common application essay question.
Best of luck!