Integrating Adobe Analytics into my WordPress-created website

I can’t use plugins due to private data

I’m not sure I follow you on this one. What has a plugin that simply injects your analytics code into the header or footer of your site got to do with this “private data” you mention?

…it looks more likely I need to manually tag all the pages.

Well, that’s an option… I just don’t get the privacy angle 😀

You’d typically put the code into your theme’s header.php or footer.php file only once, and it should appear in all pages on your website.

And you probably should create a child theme, else any future update of your theme will override any change you made to theme files.

All the best!