Hey,
*"Error Workspace 'MyProject' does not map into this project's directory."*
This is because your UE4 project files and your perforce workspace must be the same directory!
For example:
If your workspace is at:
C:/UE4Projects/MyGame/
Then your .uproject file must be at
C:/UE4Projects/MyGame/MyGame.uproject
And you have to use this .uproject file and connect to this workspace.
Error Failed to connect to source control. Check your settings and connection then try again
This one is most likely caused by an offline perforce server.
You can install the perforce server on your local machine but your mates will not be able to submit / checkout etc… if your machine is offline or the perforce server is offline.
There is a free perforce hosting: https://www.assembla.com/repositories/perforce