You can join Yahoo business if you eligible for it. Actually, it asks for your name, area, skils, age to recommend you best. So, go to the Yahoo small business page and click on the sign-in icon. Now, click on the Create Account option. After that, go into the signup page and then verify your user’s credentials. If any issues, then use Yahoo customer service number. https://www.numbersfor-support.com/yahoo-customer-service-number/