What is wrong with my first layers?
Judging by the images you posted in your question, the first layer distance is too far away from the bed for the current filament flow.

This could either be related to:


having an offset on the first layer like a height correction in the slicer,
an incorrectly levelled (read height adjusted) bed, (you did the paper test correctly, so this is probably not your problem, it is mentioned for completeness)
under-extrusion


slicer setting not correct, e.g. filament diameter or flow modifier not 100 %
incorrectly calibrated extruder



Your most likely problem is under-extrusion. It would be advised to calibrate the extruder: How do I calibrate the extruder of my printer? and check the slicer settings.