“Humans may have observed the winter solstice as early as Neolithic period—the last part of the Stone Age, beginning about 10,200 BC.

Neolithic monuments, such as Newgrange in Ireland and Maeshowe in Scotland, are aligned with sunrise on the winter solstice. Some archaeologists have theorized that Stone Age people held rituals to capture the sun on the year’s shortest day.  More history here:https://www.history.com/topics/natural-disasters-and-environment/winter-solstice#:~:text=Humans%20may%20have%20observed%20the,sunrise%20on%20the%20winter%20solstice.

Winter Solstice is celebrated in many ways over the world…

Soyal is the winter solstice celebration of the Hopi Indians of northern Arizona. Ceremonies and rituals include purification, dancing, and sometimes gift-giving. At the time of the solstice, Hopi welcome the kachinas, protective spirits from the mountains. Prayer sticks are crafted and used for various blessings and other rituals.

The Persian festival Yalda, or Shab-e Yalda is a celebration of the winter solstice in Iran that started in ancient times. It marks the last day of the Persian month of Azar. Yalda is viewed traditionally as the victory of light over dark, and the birthday of the sun god Mithra. Families celebrate together with special foods like nuts and pomegranates and some stay awake all night long to welcome the morning sun.

The ancient Roman festival of Saturnalia is perhaps the most closely linked with the modern celebration of Christmas. This festival happened around the time of the winter solstice and celebrated the end of the planting season. There were games and feasts and gift-giving for several days, and social order was inverted—slaves did not work and were briefly treated as equals.

A few more of the many, many ways to celebrate Winter Solstice here:
https://www.britannica.com/list/7-winter-solstice-celebrations-from-around-the-world