Go do some reading at https://www.error-ref.com/ and delete your YouFool bookmarks. The more BTS pocket change you post, the less and less likely you are to have people even read your posts....
Welcome to Coin Talk. It would be beneficial to you if you bought a few books on coin collecting starting with the "Red Book". The official title is: A Guide Book of United States Coins by R.S. Yeoman, et al. You can also learn a lot about how coins are made by reading: https://doubleddie.com/58201.html Plus there are many other sites that provide a wealth of information. IMO it's more enjoyable if you can do a lot of your own research. Valid questions are also welcome by the vast majority of Coin Talk members. Enjoy the hobby!
IMO just from this one photo it's a damaged coin. It's always best to provide photos of both side of the coin. Also, on the 1979 SBA dollar you posted looks like a S mint mark. Not a D/D
Thanks but to me this is DD on s mint mark an I got this coin here I no it's not worth anything just won't to show