I can´t import any files whatsoever into LRC. Please help!

I think ​@JohanElzenga has the answer. Open the Destination Panel, and make sure there is a Destination Folder shown, and that this is a folder that actually exists.

​@MZPhoto Can you firstly double check that you’ve for the right Privacy & Security Settings?https://helpx.adobe.com/lightroom-classic/desktop/technical-support/performance-guidelines/allow-permissions.html

The interface has changed slightly since Adobe did the screenshots in that document, so this might look more familiar: https://www.lightroomqueen.com/disk-permissions-sequoia-classic/

​@Sameer K Needs to move to Classic forum please.

I have two comments on your screen-clip:

1] Your photo files are already in a folder on your desktop. Do you really want to [Copy] the files in the selected folder to another location? Or perhaps you need to choose the [ADD] option.

2] If you intention is to [Copy] the files then you need to check the ‘Destination’ you have set in the destination panel.