Yesterday, I went for a walk with my camera in Yanaka. In the cemetery (霊園）, I was surprised to see so many people cleaning the graves. In Canada, we don't visit cemeteries as much as Japanese people do, and there is no special day when a lot of people go.
Maybe your foreign friends or your English teacher will ask you what you did on the national holiday (休日）this week. If you did お墓参り, you can say, "I visited my family grave," or "I paid my respects (敬意を表する) at the family grave."
Yesterday was autumnal equinox day (秋分), but most English speakers don't use those words. "Autumnal equinox" is an astronomical term (天文学用語）so we call it "the first day of autumn." We don't have a good word in English for お彼岸, so usually we say, "the period around the autumnal equinox."