how should drugs and alcohol affct my supernatral creatures?

Drugs and alcohol should affect them in whatever way best suits the story you want to tell. They might affect them the same way as they affect humans, they might affect them differently, or they might not affect them at all. Maybe something that's harmless to humans is deadly poison to some of them (like garlic and vampires). Maybe something that's (almost) harmless to humans, like chocolate or vinegar, is horribly addictive to some of them.

The way they do people. They could fly crooked when drunk.or get addicted to cocaine and ruin their health.