So, this is an odd one because I travel a lot and try to learn basic words in local languages, usually hello, please, thank you, sorry/excuse me, and numbers are my basic go to. For some reason, in a number of languages "please" isn't something you get by default. I've found this particularly in southeast Asia.
I can say please and thank you (and generally converse and read) in French and Spanish. In Spanish I find myself using "por favor" a lot. "You're welcome" takes different forms in Spanish depending where your are, and what's polite in one place can be confusing or even rude in another.
I can say hello, please, and thank you in German, Italian, and Greek. I mostly said hello and thank you in Greece and Italy, rarely please. I've never actually used German in situ, I just know it from pop culture I think.
I can say hello and thank you (and various other things) in Japanese, Chinese (Mandarin), Malay, Thai, Lao, Khmer, and Vietnamese. I might need to think hard for a minute or get a quick refresher so that I don't mix some of them up sometimes, especially when I'm moving from one country to the next... I don't think I ever learned please specifically in any of these, though I think it's kind of built into the other things you say in a lot of them (especially Thai).
So, please and thank you, 6 for sure. But if the goal is to talk about language basics for getting around as a visitor, I would say 13 :)