Basic measurements

I am having a hard time just getting started because I can’t figure out how to just show the measurements of what I am drawing. I am not sure why this is so hard. Can anyone tell me specifically how to show the measurements of whatever I put on the plot?

https://support.shapr3d.com/hc/en-us/article_attachments/11017077131036

Page 238 - Measure

Have you done any of the tutorials?