I hope you are having an awesome weekend so far! To answer your question, you should have the ability to HIDE the Setup Guide in the top right-hand corner (Blue Hyperlink), if you choose not to complete the setup.
If you have completed the set and it's still lingering it could be a browser issue and we can try the following steps:
I"m so sorry to hear that! I can absolutely relate to wanting things organized neat & tidy. I hope it gets figured out for you. Have an awesome rest of the weekend.