No matter the language, the best greeting is sincerity. You can say it perfectly with the wrong tone, and it falls flat. But a goofy, smiling attempt? That’s universal.
So go ahead. Try “Namaste” (Hindi) next time you see a friend. Or “Shalom” (Hebrew) at a coffee shop. See what happens.
Worst case? You look adorably confused. Best case? You make a friend for life. And really, isn’t that what “welcome” is all about?