I have thousands of drawings created in Microsoft Paint , now i am ditching all windows OS and going to Ubuntu , can the experts advise the best way to transition and convert my .dwg files from Paint into either GIMP or another app that will allow me to edit them ?

Secondly when i email GIMP sketches and drawings to customers , what apps will the receiver need to open them for viewing ? Will only GIMP be capable of opening them or are there other apps that can do so ?