To be honest, I’d be way out of my comfort zone doing what you do. For a start I’m hard of hearing, so bartending would be almost impossible for me. And I don’t much care for pub culture, even if I have a drink at home from time to time.
Christ had these people hanging on his every word, because they’d seen what he could do. But we don’t have miracles dripping off our fingers to attract crowds of repentant sinners. Nor are we God in the flesh.
So what He did, and what we do are two different things most of the time.
You’re more limited in what you can do to evangelise.
Also you need to be careful how you do so, as your boss may tell you he pays you to bartend rather than evangelise.
In the meantime though, you can pray. You could ask God to bring someone across your path who needs help and is prepared to ask for help. But rather than take the whole responsibility on yourself, you might need to network. Find out who the relevant agencies are in your area that help people, and make a few inquires so you’re forearmed when such a request does come your way.
You could also just offer normal Christian charity, maybe turn the other cheek when you get the inevitable drunken insult, and so on.
For the time being then, it’s a case of starting small, and playing it by ear.