Hmm my idea would be to look at the webspaces of projects in your local / regional / national area and see if they have some concept papers. Would be best to focus on those that have actual funding by the state so you can see what worked and maybe even ask them.
I found something like that for my area, but idk if you can use that considering its mostly in german. But maybe you can atleast check out the design: https://hausderstatistik.org/archiv/
Also I never designed something like that but the software I would use would probably Scribus or a pirated Adobe InDesign.