I have just obtained the software and am trying to draw a plot but when using the line there is no thickness or such and also you cannot accurately place the line where you want it because those bulbs or circles on the end of the line are in the way. When I measure the line against another line of the same length they do not correspond. Why is there no thicknesses like in a cad program or like other software.
I am stuck and getting no where and I want my plots to be accurate.

There is a problem that is part of the legacy of the system that we have not fixed. It was caused by not accounting for the borders on the objects. By the time we noticed it there were thousands of gardens built wrong and changing it without looking protecting those gardens would create a big mess.

I will look into putting a feature in the preferences for 'accurate shapes'. It would mean shapes would be the correct size, but not have the nice rounded edges. The default would be for 'pretty' and 'accurate' would be something you would need to select.

The background grid is accurate and is a good way to keep your garden the correct size.