To put things simply, it is best to expand early in Civ 6, and players should prioritize getting their first Settler out as soon as they have a Scout, some level of defense force, and potentially a Gold-purchased Builder.
While it is possible to win a game of Civilization 6 without ever establishing a city beyond the Capital, it is certainly much easier to claim victory with the assistance of several settlements. Indeed, players should be looking to build numerous Settlers and expand quite thoroughly during their games, and this guide will provide some recommendations on the optimal timing for these activities in Civilization 6.