@SteveKirby I suggest you start by cleaning the glass bed with Isopropyl Alcohol (99.9% pure IPA) to remove any oily film, including oil/grease from your fingers.
Also check the white PLA sample filament by trying to bend it into a curve. If the filament breaks easily, then it has probably soaked up too much moisture from the atmosphere. If so, I suggest you order a new reel of filament. You can dry out a brittle filament by putting the reel into an electric oven for a few hours, but you need to keep the temperature low (less than 50'C).
Start printing by printing something simple like this calibration cube: https://www.thingiverse.com/thing:1278865 and use a Brim of (say) 8mm.
Also, after leveling your bed, if you are not sure that your new glass bed is properly level across the whole area, just double check a small area near the home corner, and print the cube there (i.e. move the object in Cura slicer to near the corner, allowing for the width of the brim and then slice and print).
I hope this helps.