Sorry this is my first day using linux , when i shutdown my pc , freezing and slow here , around 2-4min ,is it normall ?
if not , to help me solve this problem ...thank u so so so much ! i like this OS , very nice and cool

Some info about hardware from Konsole could be helpful:
inxi -F

If O/S is installed on disk try this command:
journalctl -k -b -1 -e

to see kernel messages from previous boot just before (?, if any...) syncing filesystems.

I don't think inxi is installed by default, at least it isn't on my system - Neon.

You will need to install it first using the konsole.

sudo apt install inxi