Create a bootable USB drive for a clean install of Catalina on a new SSD?

Gdrenick wrote:

How can I download Catalina to a bootable USB so that I may do a clean Catalina install on my MBP mid-2012 on a new SSD?

How about Recovery or Internet Recovery to reinstall?

How to reinstall macOS from macOS Recovery - How to reinstall macOS - Apple Support

Your bootable USB query:

How to create a bootable installer for macOS - Apple Support

All new drives need to be formatted...

Erase and reformat a storage device in Disk Utility on Mac - Apple Support

I will add—

If you are moving from a HDD to a SSD, the 13" mid 2012 it is recommended to change the SATA cable at the same time—maybe there is no issue but it is a known weak link...

SATA replacement 13"MBP mid 2012

https://eshop.macsales.com/item/Apple/8211480/%20%2013%22%20MacBook%20Pro%20SATA

How to get old versions of macOS - Apple Support