I'm writing an argument essay on ebooks are better than printed books and can some one give me and example of an argument essay i'm like stressing out because i don't know how to start it i'm trying to write the best essay because the school year is almost ending and i can't mess up my grade

I would start it off on what you will be talking about. For example, you could begin with what books and ebooks are both used for.
In the first body paragraph, you explain one reason why you believe ebooks are more useful. In the second paragraph, explain why other people may disagree, and then emphasize on why you think differently. 
In a few more paragraphs, list more reasons that support your point of view and do your best to persuade the audience to agree with you. Hope this helps!