This page of the Dying Light 2 game guide contains information about the main story of the game. You will find out whether it ties in with the previous game, who the main character is and if the events of the first game have any impact on the world.
The second game takes place in western Europe. This isn't the same location as in the previous installment of the series. You won't encounter any references that will make it difficult to play the game. You can easily get into the second game in the Dying Light series without playing the original game or its DLCs.
Time after the apocalypse
Dying Light 2 takes place a dozen years after the first game's ending. Years of zombie apocalypse have made for a different world. There is no electricity or water, and people are forced to live in truly medieval conditions. A few groups live in the middle of the wasteland and need the main character's help.
The main character
The main character is also different. This time, players take on the role of Aiden, a pilgrim who travels through the wastelands, delivers shipments between human settlements and tangles with the various factions that seek to rule the fallen world.