How do I get rid of a black rectangle on my MacBook Pro screen?

I opened my mac after using it about 30 minutes prior and there is a black rectangular box on the display. I am not sure what is going on with it and confused on how to go about it moving forward. Would this be an issue that needs to be resolved with it getting fixed in store or am I able to fix it on my own through resetting?

[Re-Titled by Moderator]