Best thing to do is be nice, tell them you're from another country and you're trying to get used to the differences in road signs, etc. More than likely, if you're respectful and nice, the cop will just give you a warning and let you go.
I drive rental trucks all the time and my wife used to travel with me on business. One time I got stopped for speeding through a small town late at night. I was friendly and told the cop I wasn't use to driving such a big truck. I'm a little distracted driving the truck that I must have not noticed the speed sign where I'm sure I normally would have. I didn't realize I was speeding and didn't intend to if I did. I'll be home soon and plan to never drive one of these things again. The cop laughed, said be careful, take it easy, etc. and let me go. Attitude is everything.
