Here are resources to help you get started with Keycloak.
Here is a full configuration to easily start Keycloak with docker (in swarm mode) Take a look at the documentation.
Here is a simple guide to help you to create a Keycloak client
Here is a complet guide to help you to setup a OAuth2 'Client credentials flow'
Here is a complet guide to help you to setup a OAuth2 'User authorization request flow'