How to check and replace cells

I need help trying to figure this out. I am extremely new to formulas and very confused.

Here is my thought process: IF B1 contains a comma AND C1 is exactly "none" THEN I want C1 to be replaced with "USA".

Do I need a new column to make this happen? or could I some how use Conditional formatting? I've really only used formulas in Conditional Formatting so I'm not sure where to start.

Here is the link to a spreadsheet if you need it https://docs.google.com/spreadsheets/d/1cHtJg04BLrwvWBFaqy5VeSRJSjlA9qQcnNePZLI8u7M/edit?usp=sharing