Whether you’re going to be in Japan for the long term or even just a few days business trip, it’s a good idea to at least remember some vocabulary. If you’re an English speaker you have an advantage in that you already know lots of words used in Japanese. What do I mean by this? I’m talking about loan words. Loan words (sometimes called gairaigo) are words imported into Japanese from other languages–words such as hotel, restaurant, dinner, office, etc. (note: yes, there are native Japanese words for this meanings, but loan words are also frequently used). The good news is that loan words are often written in katakana. By spending a couple days learning katakana, you will already know intuitively hundreds of important Japanese words! This is especially handy for reading menus where no English is available.
For a bit deeper study of Japanese, there are lots of free resources on the internet for beginners. NHK has 50 free Japanese lessons in 17 languages that should get you going.