Keycloak gives your people one sign-in across the apps that support it, through single sign-on with OpenID Connect and SAML. You need someone technical to connect each app to it.
What Clusterz sets up
Keycloak and its database, at its own web address, with an administrator account. It is sized for about 1,000 users signing in.
To add it on its own, open Keycloak on its own. Install a set or an app gives the steps.
How to sign in
The username is admin, unless you chose another as you installed it. This signs in to the master realm's admin console. Add your own administrator there, then remove this one. First sign-in to an app gives the steps.
Licence
Keycloak is open-source, under the Apache License 2.0, which applies to your use of it.
Learn to use it
Training your staff stays with you. Keycloak's makers publish the Keycloak documentation.