To delete desktop icons you simply select/highlight it (single left click of the mouse) and then hit delete on your keyboard. It will ask you to confirm sending it to the recycle bin. You say YES and it should be gone.
Or you may have your taskbar up top, in which case you can right-click and unpin them from the task bar.
Or Dell might have added a docking app. In which case if you don't use it I would probably uninstall the app.
If none of these ideas help then attach a screenshot with your next post so we can see what you mean.