Bill, most of the time you don't need to talk Spanish on a visitor's few months stay. But you will like it better if you can talk a little. Anything, from grocery shopping to minor repairs will go faster and more efficient. You will make fewer costly mistakes. Most Mexicans are polite and patient in your attempts to communicate, but it doesn't mean they like it and they might not have time. It's better to know at least some Spanish.
They will appreciate if you are trying to talk some, and it is not difficult and doesn't cost money to make this first step. You can download free Spanish dictionary in Android, it's called Xynotec - they have other languages as well. And you can learn how to build basic phrases like "I need ...", "where is...", and numbers. Polite phrases like "Excuse me" before saying that you need this or that, will help more than you can imagine. Their culture is very traditional, in some ways almost as formal as Victorian English society, despite low standards of life.
I don't know what would be the best way to learn - there is no easy way after you turn 40-45, and for some people it's more difficult than for others. But you may try. I like Standard Deviants DVD series, it should be available in your local library, the first 2 discs contain all the basics. Repetition is the key, at our age. Watch it again and again, write down the phrases and words - Spanish in one column and English in another, and repeat with Spanish column covered with a sheet of paper. Leaving legal aspects aside, let's say that it is possible to record the library DVD into your computer for further studies at home, people are doing this all the time. Or buy it, it doesn't cost that much.
Automated voice translators have never been good, the chances of getting it totally wrong are high. Xynotec dictionary has a voice option if you need to hear the word, though Spanish phonetics is straightforward - it will sound just like you see it.
Yes, what Mex said - "I have a question" - pregUnta, accent on U. Wouldn't also hurt to say Buenas dias (or buenas tardes, or buenas noches, whatever the time of the day is), before saying this. Then you may point on your map, or broken RV part, or empty water container, or whatever your problem is, and go on in your Ingles or sign language, or both.
Don't want to go into endless list of suggestions, but this is something related to langguage: unless it says $US or USD, or DLS, always assume that $ sign on the price tag means Pesos. If you are in doubt, ask "Este precio es dolares o pesos?"