I'm having issues with editing the header, I want

If you already have multiple pages in the document, go to your header. Click into it like you're going to edit it. This should open up the Header & Footer Tools tab on the ribbon (ie the giant menu bar at the top). Click on this.
On the Header & Footer Tools tab, 4 groups over from the right is a group called "Options." Make sure that the "Different on First Page" option is checked.

If you set up your header before you check this box, the first page header will delete itself. No need to panic, just copy it from the second page and then set up the second page header to your liking.