If you want to set Yahoo as a homepage on Google Chrome, then you have to follow the correct steps according to your browser.
1. First of all, click on the menu icon and go to the "Settings" option.
2. Scroll down the page and click on the "show home button".
3. Now, click on the "Enter Custom web address"and there you have to enter you Yahoo address which your want to make homepage
4. Scroll down again and select the option "Open a specific page or set of pages".
5. Then click on "Add a new page", enter the site URL and click on "Add".
6. After that it will make Yahoo as a homepage automatically.