How do you address people that are acquaintances but you don't know their name? Not that you've forgotten their name, you just don't know them well or you're just interacting with them for the first time.

I have for a long time, referred to men as "brother", but a Youtube video I watched made reference to that being a "Christian" term. Also I realize that used in the wrong context "brother" could actually come off as racist. I don't refer to women that are acquaintances as sister because I find that weird. Couple that with the idea that many people are trying to use pronouns that are genderless. So what do you use?