Open BeamNG.drive
Go to the main menu
Select Repository
Browse available maps
Download the map you want
Wait for the download to finish
Enable the map in the level selection menu
Start a new game on the installed map
Use the BeamNG official forums for additional map mods
Download map mods from trusted sources
Extract the mod files if needed
Copy the files into the BeamNG.drive mods folder
Restart the game
Check the map list again
Enable the modded map if required