Below are some guides to OAuth 2.0 which cover many of the topics needed to understand and implement clients and servers.
OAuth 2.0 Simplified, written by Aaron Parecki, is a guide to OAuth 2.0 focused on writing clients that gives a clear overview of the spec at an introductory level.
OAuth 2.0 Servers, written by Aaron Parecki and published by Okta, is a guide to building an OAuth 2.0 server, including many details that are not part of the spec.
There are many client and server libraries in multiple languages to get you started quickly.
You can find some excellent books on OAuth 2.0.
Find an OAuth consultant to help your organization.