Ok that looks like some standard post processing. Mechanical APDL has an 'processor' style workflow meaning for example to solve we have to be in the 'solution' processor. For reasons almost lost to time the time-history post processor is /post26. Contrast with /post1 which is post processing to create contour plots of some result at a specific time/frequency.
This Forum is not a good place for training. If you are a commercial customer review the MAPDL Help -> Basic Analysis Guide -> Time History Postprocessor. If you are a student does your school offer the help on-line?
You are navigating away from the AIS Discovery experience