C# with SP-API for VS 2019 sample routine

Hi,
I need to consume the SP-API c# web services; and have read all the documentation; created all the necessary logins, keys, secret keys etc; and am now at the stage of creating an initial sample c# application to test these API’s and see what comes back.

However the documentation, especially on Github is very confusing and appears to have assumed knowledge; which in effect leave ‘gaps’ in the ‘how to’.

Does anyone have a simple, sample c# routine for use inside Visual Studio 2019 c# Console application including specifically step-by-step instructions on how to include the SP-API routines as published in the documentation? Are you willing to share here?

Any help greatly appreciated; as the process is proving to be very frustrating!

Thank you.