Its a cool coin but not a rare coin.
It's a free dug coin and it's yours.
I dont usually give suggestions on whether to clean or not to clean but I will say this...water will kill a copper coin.
If it's good enough as a keeper for you then do nothing but it does deserve more attention being a nice early state copper.
If it was mine ..I'd give it soak in hydrogen peroxide to get the outer gunk off...hydrogen peroxide wont disrupt the patina like water will
Let it air dry and then wax it.
Simple and effective
What ever you decide keep us posted on your choice