After configuring the playbook, you're ready to install.
Run the playbook: make setup-all.
After installing, you can start services: make start.
Gitlab may take a minute or so to actually start.
After some time, you should be able to access your new Gitlab instance at: https://gitlab.DOMAIN.
Going there, you'll be taken to a "set new password" page, which will let you assign a password for the default root user.
Feel free to create more users after that and even delete this root user.
After you're convinced that Gitlab is running, you should finish-up your configuration (what you started doing during configuring).
In the future, if you are to restore a backup or otherwise rebuild the Gitlab server, you'd wish to also restore the SSH host keys for the Gitlab Shell server.
The backup/restore process doesn't take care of those, so you should let the playbook help you.
Edit your inventory/host_vars/gitlab.<your-domain>/vars.yml file and uncomment and populate the gitlab_shell_ssh_host_keys variable.
The SSH host keys are in /gitlab/gitlab/data/ssh (gitlab_gitlab_data_ssh_dir_path) on the server.
You can paste the content for each key in the corresponding place in gitlab_shell_ssh_host_keys.
We recommend encrypting the values using ansible-vault encrypt_string.