I will begin with one of the most important signs for a tourist, especially when you need it. The sign for restrooms can vary, but this green "toilettes" sign is a typical one pointing to public restrooms. Also look for signs that state "W.C." to lead you to a restroom. Be sure you have change handy, as it is common for public restrooms to be paid.
Continue your tutorial and virtual tour of commonly-seen street signs by moving on to the next step.