I find it very difficult to use curves in blender. I used to use Corel Draw X4 but it does not work on windows 10. Is there a free program which I could use for 2D drawings which could then be exported to blender ?
I understand anything that will export/save 'SVG' files. SVG can be imported into Blender. There's quite a few questions about how Blender treats SVG in here.
An SVG option under save/export has rapidly become fairly standard for most vector drafting applications. I'm not up on the free stuff right now, so I'm afraid you'll need to do the leg work to find out which one's will save SVG files. Hope this helps.