This tutorial is to change font and size on a specific areas with Easy google font plugin. Follow all these steps. Go to Settings > Google fonts to add the selectors.
Go to Apperance > Customize > Typography. Set up the entire theme fonts in “Default typography” tab. To modify the text in a specific area (the selectors we just created in steps 1 & 2), click “Theme typography” tab. You will see the font control name we created in Step 1 here. Set up everything just like how you want it to be.
Publish the page.