RE: API connection to Dynamics 360
Hi Ivan,
There are a couple of ways you can do this -
1. You can use IOrganizationService interface to connect to dynamics 365 from your C# plugin that sits in Dynamics or from the Console Application.
2. You can even use WebAPI to connect to Dynamics 365
Here a few links that explain this in simple way -
Microsoft Documentation - docs.microsoft.com/.../gg328282(v%3dcrm.8) (This should be the ideal way to explore ways to connect and get helper code as well)
Using Console Application
arunpotti.wordpress.com/.../comment-page-1
Hope this helps!