Yes, once you are happy that the OneDrive version is working to your satisfaction then you can delete the ‘This PC’ copy.

Just check one setting. Right-click the OneDrive cloud icon in the Navigation bar bottom right and choose Settings.

In the ‘Microsoft OneDrive’ dialogue open the ‘Settings’ tab and ensure that ‘Files On-Demand’ at the bottom is NOT ticked.

Otherwise, if you have no Internet connection you may have no FH Project files on your PC.