polygonal generator c#

Hello im trying to make a polygonal generator in c# and im having trouble getting started i cant find any resources that explain the concept right or the end result isn't what i need.I'm trying to make a map like the one in Hearts Of Iron 3 but smaller as well be a bit like Call Of War 1942. this is my first time working on a 2d project i started with 3d projects, so im kinda lost in the 2d aspect of thing.alt text