I´m trying to get the exact shape or path from the following image.
I was using Visual Studio but it still makes me difficult to write point by point.
I guess there´s another way or software to draw this better, and a little hand about how would be those points in xaml.
Thanks in advance!

To answer your first part of your question, here’s an example (you can play with the Stroke & Fill Color obviously to get what you want.)
WPF Sample:
As for the second part to your question, personally I primarily use Adobe Illustrator with a XAML Exporter plugin made by Mike Swanson (http://www.mikeswanson.com/XAMLExport)
Or, I also quite often use Microsoft Expression Blend for all sorts of related things. Hope this helps.