TL;DR: drinking yes, and willingly, smoking is debatable.
Drinking — yes
The first two images are courtesy of the answers to this question.
In this one, Superman is powerless after using the "Super Flare" power (basically unleashing all his energy, rendering him powerless for some time after). So the getting drunk part is because of the powerlessness, but Clark Kent/Superman presumably still has all the ideas about the American Way etc, and is drinking alcohol willingly. (comic: Superman (2011) #40)
Then there's this one, where it's not always exactly pictured, but clearly stated. Superman gets picked by a boat the crew of which thinks he's Bruce Wayne, poses as him, and drinks several glasses of champagne while doing so (one of them was drugged by Deathstroke).
Agreed though, you could say that in this issue he wasn't Superman yet (as in, still "constructing" himself). (comic: Superman: American Alien #3)
(that's probably not orange juice)
(two glasses, both almost empty)
There's a couple other pictures in this comic, but posting them all would be posting the entire issue, ahah.
Smoking - no, but...
Stumbling across Google Images, you could encounter this: (comic: Superman #163)
So, not smoking for the thrill of it, but merely as a cover method. But, he was also under the influence of Red Kryptonite at the time, making him goofy. (and also, it was the 50's-60's...)
So, no smoking, and there are instances of him campaigning against tobacco ("Never say yes to a cigarette", and the Nick O'Teen villain). On the other hand, early on, he sometimes used heat vision to light up cigars:
(these three images taken from this source)
Then again, one could argue that the first one was for show, and the second one was an act of kindness for a guy who was already dying. Also, as said earlier it was the 50's-60's, when there was not as much "public awareness" of the dangers of nicotine/tobacco/etc as today.
Bonus section: Superman drunk in movie
While not included by the question, it is worth mentioning "evil Superman" (poisoned by pseudo-kryptonite) who among other vices becomes drunk in Superman III.