Upvote:1
Personally, I've found the language learning app Duolingo to be useful for learning the basics of a language. Duolingo (and its many competitors) rely on spaced repetition, meaning it remembers what you got wrong and right and drills down on your weaknesses.
Now I need to emphasize the "basics" here -- you're not going to get anywhere near fluency -- but if you want to learn exactly the kinds of basic greetings, numbers, simple food vocabulary etc that you mention, it hits the spot, and as little as 30 min a day can give a perceptible leg up. It's also quite good for drilling non-Latin scripts if you want to try to learn to read the language as well.