I have a document divided into 2 sections with headers and footers
already in place. I want to change the header in the 2nd section to a
"first page header". I tried going into page setup and checking the
"Different First Page" box in the layout tab, but nothing happens.

Also, even though it appears to be the first page in the section, the
page numbering started at 2. I checked the page numbering under the
Page Number Format window and it does state that page numbers should
start at 1. By changing this to a 0, I got it to change the first
visible page of the section to "1".

Should I just start over with the headers? How?

I hope this was clear and thanks in advance