Clone following projects in one folder:

Link	Description
https://github.com/FNA-XNA/FNA	FNA
https://github.com/FontStashSharp/FontStashSharp	Text rendering library
https://github.com/rds1983/XNAssets	Assets management library
https://github.com/rds1983/Myra	Myra

Now add every required project .FNA.Core.csproj to your project