If I wanted to share a correspondance game I played here on chess.com is there a way to "copy and paste" the moves into the tool that lets you put it into the posting, or do you have to write it down and enter it by hand.?

go to your archives of games, click to open it, find the option called Get PGN. Open that -- it will open in notepad, or something. Click the chessboard icon, and paste that PGN text into it. It will give you options to add comments.