How to make a disk partition?

[Siro]

Excuse me, do any of you know how I can create a partition on the hard disk?
I tried with Gparted, but it won't let me make a partition that is smaller than the size of my disk.

I also tried from the default disk application, but it didn't allow me (I think it's because the disk is being used).
Can anyone help me?

[Hackgets]

Returns the error because the disk is in use. It is necessary to boot from another device such as a USB drive.

[zabadabadoo]

@Hackgets

Returns the error because the disk is in use. It is necessary to boot from another device such as a USB drive.

e.g. run gparted from your ZorinOS Live disk USB drive.

[swarfendor437]

Yes, to be precise, run live usb, run Gparted and then 'unmount' the partition - you should then be able to resize the sda2 partition (make it smaller), then create a new one after it.