The first error is telling you that another instance of Ghost is running on port 2368. This is set in production.config.json and may be set using the ghost config --port 2368 option. Are you running more than one instance of Ghost? If not, then something else may have gone awry.
The other messages relate to systemd. This can be set using ghost config --process systemd.
After making any changes, you should run ghost restart.