I can't set up my Viewports to the correct scale to export to pdf. Or do anything else with them at all.

There doesn't seem to be anything in the manual except how to create all sorts of viewports, not what to do with them.

When I try using scale in the window to the left after selecting the port I just get an error message about some locked object being deleted and the model shoots out of the window.

I can't find a tutorial anywhere about how to set paper sizes for your viewports and scales within them of how to use them at all.

Can anyone point me at a tutorial or something?

Preferably not a video one.

Thanks.