I guess not. You can set to Legacy in your BIOS, prior to proceeding.
Or, you can make an EFI partition while you have that Gparted partition Manager window open.
If you prefer Legacy, "go back" and then quit and reboot into your BIOS settings and set to Legacy.
If you prefer EFI (recommended), it is fortunately much easier to create the EFI partition now than it would be after the install.
Select "Create New Partition"
Set the format to fat32 and the size to 400megabytes.
Go to Manage Flags and select boot and esp.
Once done, click apply.
With that done, in gparted, continue where we left off above.
Calling at @337harvey to look this over as he is better at this than me.
It's your choice. You can partition, then move partitions or just wipe the whole thing since this is not a dual boot and can be wiped.
Going clean and fresh and non-dual boot means you can afford the luxury of not having to worry much.
If you were trying to dual boot with Windows, that held valuable data, you would be sitting upright so tight a person couldn't get a needle in ya with a sledgehammer.
Also: A point. We are happy to help as able here. But as a user that chose Zorin OS Pro, this comes with Installation Support from the ZorinGroup directly.
So if in a bind, do not hesitate to use that and send a message from the link in your confirmation email or from the main site:
