Red at the bottom means that the category that was created from the items in the template is not a current category, usually meaning something is misspelled or not formatted correctly.
Branch has to be spelled out as United States Army.
Start and end date have to be a date. If you don't have them, leave those parameters out of the template.
Unit and units would only be Pennsylvania, I think.
In the enlistment Source, Harrisburg, PA is where he resided or enlisted, but he would normally just go into the State unit which is what is shown on his gravestone.