Please follow these steps to join an existing Assetto Corsa Competizione private server:
- Launch the game and from the main menu, select Multiplayer.
- Select Server List in the bottom-right section of the Multiplayer screen.
- In the server menu, navigate to and select your desired server, or you can search for the server name manually at the top of the list.
- Select the server, and when prompted, enter the server’s Password.
- Select Confirm and good luck on the track!