How can I store my variables in yml file?

I have just started to learn Selenium Testing and I started to test login function in the website. I would like to write standart test which is applicable for any website. Thats why i would like to keep my variables in seperate yml file. How can i do it, please help me. Many Thanks

when i tried to write my variabled under my acceptance.yml i have received below error;

Error loading Yaml config from /app/customtests/tests/acceptance.suite.yml

You cannot define a mapping item when in a sequence at line 2 (near "email: 'test@gmail.com'")