I made this map for a mentored dove hunt. I put points every 40-50 yards I think for pin locations. You select a start point and work around your area. You can do different mapping features like acreage and size or distances.
I’m on my phone and if I get time tomorrow I’ll try to get better examples when I’m on the computer.
What are you looking to do with the rectangles? How accurate are you looking for? You may be good getting photos and mapping with measurements you’ve made on the ground with a tape. Then you can put them on the map yourself with a compass and a pencil like doing dead reckoning with navigation.
Download Google Earth Pro. It's free. You can draw "paths" or "polygons" and other stuff on the maps to mark boundaries or trails. You can import any image, such as other maps, nav charts, etc, and stretch and adjust them as overlays to line up with the base map.
I drew the boundries of a bunch of state lands, overlayed a navigation chart of the Delaware Bay, and overlayed a map of shell fish regulations in the images below: