I have an Ender 3 Pro, and really have not had any issues aside from the setting the nozzle to the bed. That is critical to get it just right, as you see you are having trouble setting.

A business card, depending on the card stock, may be too thick.

Remember, when you are adjusting your bed to turn the nozzle and the bed temperature to your setting and then adjust. Follow this video off youtube: ENDER 3- Easy Way To Level Your Bed

and download his gcode from the links below the video...THIS IS A LIFESAVER. Sorry dont have enough post count to link the video.