You should take it to a data recovery specialist if the data is really really important but for lightly-damaged sectors, you want ddrescue (oldie but goodie) or HDDSuperClone (no longer developed) or OpenSuperClone (fork of HDDSuperClone, more actively developed).
You can combine some of these tools with commercial programs like dmde, UFS Explorer, or R-Studio - to target specific files for a quick result - but basically it’s best to get a full disk image off the bad drive onto another drive/image.
While you can do command line stuff with CloneZilla, I think what they’re referring to is the TEXT-based guided user interface, which doesn’t seem to differ much at all to the Rescuezilla GUI, which only looks marginally prettier. However, there’s a few other useful tools in there, and a desktop environments, so it’s still a bit nicer to use.