If you shut down power, you may damage the SD card with incomplete writes. It may or may not reboot and operate reliably.
If you can log onto the pi via ssh, (good helpful forum posts on ssh also) then you can issue the command: sudo shutdown now
The now option above immediately shuts the system down and your ssh connection will drop. The pi will shutdown completely within 10 seconds, and only the red light for power will be on. The yellow light will flash when reads/writes are going to the SD card. I usually wait until the yellow light stops flashing, wait for a couple of seconds then you can safely remove power without harm to the SD card.
We all have to go through this learning curve and as we learn more it gets easier. Just a note, you can use the up and down arrow keys and scroll through previous commands you used previously. That saves a lot of time when there is some command you commonly use. It helps to reduce typing mistakes for me. Have fun with your system.