How to retrieve users in azure ad using graph api via aspnet mvc

Question

I am developing an application using aspnet MVC. It is implemented standard .net framework 4.8. I have already implemented the Azure AD integration with Owin middleware and it is working perfectly. Now I need to retrieve group, user and membership data to extend my authentication. Can you suggest simple example to retrieve user, group data using graph api. If there is any other way please share the references. Please note i am using standard .net framework 4.8 not .net core.

Thanks in Advanced,