If you are interested in “comparative” measurements (comparing one piece of equipment with another), then this topic may help: https://forum.audacityteam.org/t/distortion-analyzer/8218/1
If you want absolute (calibrated) measurements, then you may need proper test equipment.
If you want to attempt making your own test equipment, there is some information here that may be useful: https://www.evaluationengineering.com/measuring-snr-sinad-and-thd-quickly