On the controller of the PS5 press the middle button.

That's it.. PS5 is on and you have lots of games... Enjoy!

As games are big, not all of them are installed.. If you want you can chose some from the library - just go all the way right and click "Game Library"

And after that got to "Your Collection" - there are all of the games downloaded (about 150 for now) and you can install some if you want (if there is space - if not you have to delete some to make space)

To turn off the PS5 press again middle buton once

Go all the way to the right and press "X" on the power buton

After you pressed "X" on power button just choose "Turn Off PS5"