How it feels to get high will differ depending on the types of drugs you are doing, the dosage, and on you as the individual. I don't know what drugs you are specifically curious about or if you just mean drugs in general, tbh.
I don't really have much experience with drugs outside of shrooms, weed, and alcohol.
Being high on weed for me makes me feel good, but it also makes me slightly more paranoid than usual. I'll usually find myself thinking that people are watching me or talking about me when they really aren't. Colours become slightly more vibrant, and my memory becomes worse. If I were to walk a short distance I would usually find myself stopping and turning around every few minutes, having trouble remembering what happened prior (it's a bit hard to explain in words, so sorry if this sounds a bit clunky). I become more easily distracted, and I have a harder time thinking clearly. It's like there is this sort of cloud covering my thoughts. Food tastes pretty good (better than normal), and music sounds better (at least when I can concentrate on it) on weed. I feel dumb while high on weed, and it's great. I don't do it too often these days, though.
Shrooms are amazing. I usually only do them around once or twice a month. They can make you nauseous sometimes and the bodyload sucks, though it usually goes away after the come up period. You start seeing these patterns while high on them, and you may notice objects changing in size, the walls breathing, things moving, etc. Colours become more saturated and usually, during the come-up period, you kind of have "HD vision". Basically, your visual acuity increases. Your sense of self also starts to fall away. It's to a point where it feels like the barriers between you and the environment start to weaken. I tend to find that I can think much more clearly on shrooms compared to when I'm high on weed, and I find that my introspection tends to be more intense while on it. My inner voice becomes louder and more salient. Your emotions can also become more intense. I find that I tend to have more ideas and create more connections between different concepts while high on shrooms (it also happens on weed, but to a lesser extent). I also find that I question things more while high on shrooms (the same thing applies to weed as well, but, again, to a lesser extent). My appetite is usually suppressed while I'm tripping, and eating tends to feel like a chore. I love listening to music while high on shrooms. Music sounds good while high on weed, but it sounds full-blown euphoric at times while high on shrooms. I honestly love shrooms. I find tripping on them to be very fun, and usually I sometimes experience afterglow once the effects wear off.
In all honesty, I feel like to fully understand what it is like to be high on either of these drugs requires that you actually experience them firsthand, especially in the case of shrooms. Even with the descriptions I've given, I don't feel like they provide the full picture of what it's actually like to be high on these substances.
Whether or not your experiences with substances will be good or bad depends on many factors. Your genetics, setting (especially in the case of shrooms and other psychedelics), headspace (especially in the case of shrooms and other psychedelics), dosage, and so on will all have a strong impact on your experiences. Most of my trips have been good.
It's not a good idea, yes, in the short term, but it hurts you in the long run. They destroy us even more. Enough with medication when you're sick, that's enough.

That depends on the type of drug, your genetics, environment, and why you are taking said drug, etc. Not all drugs necessarily destroy you long-term.