Can you get covid from signing a clipboard after someone else touched it? would the viral load be enough?

COVID 19: Although possible, it is important to remember that droplets are the primary mode of transmission. If the materials you touched were contaminated, simply washing hands with soap and water should remove it. You would need to touch your mouth, nose, eyes with contaminated hands to infect yourself.

Fomite as cause?: Immediate touch of contaminated surface or object can transmit the virus. As it is highly virulent, small contagion can be enough depending upon host response. Frequent cleaning the surfaces, objects and hands is protective. Gloves if changed frequently can help as well. I hope it helps.