Installing Zorin OS on a stand alone HD via a USB

I want to install Zorin OS on an extra external hard drive I have using a USB. I know I need to format the drive. Not only that, but I already have the OS burned to a USB using Etcher so it is ready to go. My question is can I skip the partitions part and go directly into install since I will be using all the HD for Zorin? Thanks.

To avoid confusion, I would advise removing/disconnecting any other drive, including the internal drive so the correct drive is written to. Then when you run the installer it will install to the correct drive. When you run the installer you will eventuakly see a window with 'Erase entire disk to install Zorin' - choose that option.

Respectfully my question was may I skip the partition part of the installation since I will be using the entire disc for Zorin? Thanks.

That is what the option to erase entire disk does. No partitioning. However, manual partitioning is better because you can reinstall the system without touching your /home partition, so be sure to make regular backups of your critical data.