Don't know where to start

I am a C++ developer and have never used GitLab before. I am familiar with TortoiseGit, BitBucket and Jira though but we are transitioning to GitLab soon. I have been placed on a new project and need to become GitLab fluent as an admin and learn how to configure workflows. All of the tutorials I have seen so far have been very generic so I already know the basics of how GitLab is used. I’m looking for practical concrete examples of GitLab in use. Can anyone point me to any resources that may help me? Thanks in advance.