black coffee is basically an essential of this. Adding just about anything to it is a no-no.
To my reckoning, red bull is basically poison. The costs vastly outweigh the benefits. I wouldn’t drink one of those things (anymore) under any circumstances.
Caffeine alone will not affect you e.g. black coffee/pills etc.
Manufactured beverages contain all sorts of other substances than can mess with you- artificial sweeteners and so on.
It’s individual- try it and see.