i have a soccer ball on my home screen. it's above my name. I don't recall how it got there. how can I remove? it?

Every account has an image. The OS randomly assigns one when you create an account. If you don't like it, change it to something else.

System Preferences > Users & Groups

Highlight your user name if it isn't already. Click on the larger icon to the right of the left column (the word Edit will appear). Choose any other image you want.