I found this information searching Google [systemd-cheat-sheet] link
#VIEW systemd INFORMATION#
###THE systemd REFERENCE CARD ###
####LISTING SERVICES####
systemctl list-dependencies Show a unit’s dependencies
systemctl list-sockets List sockets and what activates
systemctl list-jobs View active systemd jobs
systemctl list-unit-files See unit files and their states
systemctl list-units Show if units are loaded/active
systemctl get-default List default target (like run level)
####WORKING WITH SERVICES####
systemctl stop service Stop a running service
systemctl start service Start a service
systemctl restart service Restart a running service
systemctl reload service Reload all config files in service
systemctl status service See if service is running/enabled
systemctl enable service Enable a service to start on boot
systemctl disable service Disable service--won’t start at boot
systemctl show service Show properties of a service (or other unit)
systemctl -H host status network Run any systemctl command remotely
####CHANGING SYSTEM STATES####
systemctl reboot Reboot the system (reboot.target)
systemctl poweroff Power off the system (poweroff.target)
systemctl emergency Put in emergency mode (emergency.target)
systemctl default Back to default target (multi-user.target)
####VIEWING LOG MESSAGES####
journalctl Show all collected log messages
journalctl -u network.service See network service messages
journalctl -f Follow messages as they appear
journalctl -k Show only kernel messages
####USING UNIT FILES####
Besides services, most systemd commands can work with these unit types:
paths, slices, snapshots, sockets, swaps, targets, and timers
My input below
###Investigate System Start Up###
systemd-analyze
systemd-analyze critical-chain
systemd-analyze blame
systemd-analyze plot > plot.svg
systemd-analyze verify command prompt return if no errors