Travelling to paris with my wife as a surprise get a way from the UK to paris for 3 nights in feb. Staying at the courtyard paris boulogne which is close by to metro boulogne jean jaures...wondering what's best way to travel around paris to the attraction sites?? Metro bus rer etc? Also worthwhile getting a 3 day pass or "carnet" of tickets? Could you use same tickets on metro and bus? Thanks in advance!