List all active services with:
systemctl
add --all to show inactive ones, and list-unit-files to show all with files.
systemctl status <service>
# for example for CUPS printing:
systemctl status cups
In addition to status, you can run start, stop, restart, try-restart, reload, and force-reload.
To monitor daemons, use journalctl. This command shows the most recent lines:
journalctl -xe
and this shows just for a given service:
journalctl -u <service>