If you’re interested in learning the language, but don’t have 3 years to prepare:

Jisho.org is an online English-Japanese dictionary that helps you find words by selecting radicals from a chart. You can learn to break down 99% of common kanji into their radicals within a week and then it’s a matter of selecting 2 or 3 radicals in the chart and matching the picture. Finding all the kanji in a sentence (or more likely, the three kanji on a menu item) should give you a decent idea of the full meaning. Now you point at the menu, say the standard question from your phrase book, give a polite nod, hold out your money at the appropriate time, and you’re nihongo jouzu.