Shopify developer - Adding Tab to Header

Hello. I'm looking for some custom shopify coding that will enable me to add two tabs to the header of a website. I would like to give the appearance of two stores, with the second tab linking to a custom page within the same shopify site. I've included an example of a live store that currently has this setup as well as snapshots of my store (I got half way there and couldn't complete it myself). Please provide a quote if you can assist. Thanks!

Example site: https://www.minimioche.com