The available history fields vary depending on the version of the model, and there are numerous versions of WACCM with different chemistry and physics packages. Whenever the model is run, there is a complete list of available history outputs listed in the atm.log file after this line:
******* MASTER FIELD LIST *******
As an example, I have attached the full master field list section that I cut from an atm.log file generated for our first CMIP6 WACCM6 historical run with full TSMLT chemistry (b.e21.BWHIST.f09_g17.CMIP6-historical-WACCM.001).
Of course, these are just for the atmosphere component. If you are looking for history outputs from the surface models, you might try looking at their log files (ocn.log, ice.log, lnd.log, rof.log, cpl.log). If it is not there, we can ask someone else to help you.