1980 Dime Not Pretty Needs Cleaned And Much More But Very Confused

A couple of things... first, no matter what, please please never clean any coin. It destroys any numismatic value it may have. Second, never hold your coins between you fingers or where in could come in contact with your skin. Your skin has oils that can damage the surface of coin, especially shiny ones. Better is to wear inexpensive cotton glove available anywhere hobby supplies are sold. Your dime has extreme circulation damage, post mint.

Yes, " cleaning" wouldn't hurt it because it's so far gone, and same for handling your coin without gloves, but if you get in the habit of treating each coin as if it was a thousand dollar coin, if/when you do come across a valuable coin you will have protected it from further damage. If you are serious in learning about numismatics, you'll treat every coin with respect. Many beginners have ruined coins because they don't know about proper coin handling. Now you know. Treat your coins well and may be rewarded someday for your efforts.

Classic acid damage. Use the search box upper left of page and you will see a ton of info on it.
John1

Yep, a weak acid solution will dissolve the pure copper core before it does the coper/nickel cladding thus creating the channel you see. I have a quarter that looks just like that (only larger).