Martin Luther had a number of ideas for things that people could do at home to teach the catechism to their children. He certainly didn’t invent the wreath itself, because that goes back to ancient Roman times, and probably even earlier. People used wreaths as an Advent decoration long before Luther, but Luther may have used the wreath as a Christian-education device and thus popularized it. I suspect he had a hand in it because the Advent wreath in its present form started in Germany as a Lutheran family custom. Since Advent wreaths were originally used in the home, most of the ones you find for sale are small. They didn’t become popular in churches until the middle of the twentieth century. Now they are nearly universal.
You can make an Advent wreath with either four or five candles. Just a note some churches use blue candles instead of Purple.
First Sunday in Advent
Second Sunday in Advent
Third Sunday in Advent
Fourth Sunday in Advent