My father has been in the bar business the majority of his life
But really, it depends what kind of "bar" atmosphere you want and who you intend to cater to, which would also depend on your locale.
For the most part he owned typical "taverns"....little joints for his patrons to stop in after work, though once or twice a week he did have local bands play.
He never was into the whole "night club" atmosphere, though his last was that atmosphere....and he said it was a really headache

Dealing with "young adults", violence, weapons, etc. and yea, he defintely had bouncers lol.
His first bar though, was pretty laid back, he had a couple bar tenders (females) and didn't need any bouncers.....really, in his prime he was nobody to mess with

So he did the "bouncing" himself if necessary lol.