App on MacBook won't delete?

I downloaded an app on my MacBook pro 13 inches few minutes ago, and now I want to delete it but it's not deleting due to the fact that app is still open.

I tried closing the app to be able to delete it but it's just not working! And when I want to open the app, it says that the app is incomplete or may be damaged. So now I can't close, open, or delete the app. Help?

-Tell me how to delete or close this app with steps and details please. Thank you!!