A multisite with a landing page

Please help me,

I need to create a woocommerce site with an initial landing page where the user will be able to select different stores based on his location using a simple drop down. How can I do that?
Also the landing page should be needed only for the first time if he selected a location based store before.
The landing page url should be for eg: https://www.google.com/fggf and not https://www.google.com.

Thanks in advance.