It kinda depends what your level is now and what your goals are.
Duolingo is good for reading/writing, learning a bit of grammar, and expanding vocab, but it won’t help you speak or listen. If your goal is just to learn a few phrases before the trip, then I probably wouldn’t use Duolingo.
If I just wanted to learn a handful of phrases, then I’d probably search a YouTube video for useful phrases and go from there.
If you wanted to get really serious, then there are a lot of tools at your disposal. One on one classes with a tutor on italki or Preply could be useful down the road once your level is a bit closer to conversational.
You could check out this thread for more ideas: Learning to speak a new language as an adult (experiences, struggles, tips, stories)