it still comes up on the yahoo browser
Yahoo doesn't really make a browser. There's a custom version of Firefox specifically designed with Yahoo users in mind, but....
Yahoo is just an internet company who has a website called Yahoo.com
You pick your home page based on your personal preferences and you can change it whenever you want, which ever browser you are using.
I have Chrome installed which always opens to Google.com (Chrome is a browser and google.com is a website).
I have Internet explorer installed and it always opens to msn.com (Internet explorer is a browser and msn.com is a website).
Someone might have Firefox installed and it might always open to yahoo.com but still, Firefox is the browser and yahoo.com is just a website.
I open chrome and search something, it still comes up on the yahoo browser
IF you're gonna use Chrome then my suggestion would be to set Chrome's homepage to
https://www.google.com and make sure you are also using Google.com as your preferred search engine.
Chrome's settings page: