what are some examples of scale and proportion? can i have a few examples for each?

https://www.google.com/search?q=scale+proportion+in+painting&oq=scale+proportion+in+painting&aqs=chrome..69i57.8444j0j7&sourceid=chrome&ie=UTF-8

Read lots and read carefully. Click on Images at the top of the search results if you don't find enough of what you're looking for.