Load Cell and HX711 only outputting 0's
This line is where you are reading the data and printing it:

Serial.print(scale.get_units(), 1);


The 1 on the end of the line defines how many digits you are displaying from your reading. I have a similar setup to yours and I have it set to 5 which shows up to +/-0.00001kg. (Obviously, the accuracy will be different depending on which load cell you have)