Does anyone have any ideas on how to make a ground plane in Altium 19.1? I have seen some guides but they appear to be in an older version of altium. I am also very new to PCB design and I know next to nothing. Any help is greatly appreciated.
Assuming what you want is a Polygon Pour (ground plane around the signals/ components)...
The procedure is the following:
Go into the "Polygon Manager"
When you are in this dialog box you can then make "New Polygon from"
And I usually like to create it from the board outline, which will create a polygon pour over all remaining space on the selected layer.