Do new files you create in SU 2018 look ok?
If so, I don’t have a clue where the problem lies. SketchUp 2018 should be able to open files from older versions (though not vice versa), and certainly without the kinds of distortion you report. It would help if you could upload a .skp model file instead of images so we can see if we also have problems.
If not, it is likely that your graphics adapter and/or its drivers aren’t up to the increased OpenGL requirements of newer versions of SketchUp. There was a major rewrite in 2017 of how SketchUp uses graphics hardware. Your profile doesn’t really say what graphics your computer has, though “HP built into laptop” leaves room to suspect it may be Integrated Graphics. If that’s the case, you could try obtaining newer drivers from Intel (or whoever made your graphics) and see if that helps.