I’d suggest editing your single template, instead of functions.php. So, in a child theme, edit single.php and whatever other templates your theme uses for the CPTs, at the location where it outputs the author’s name.
Where the author’s name is being displayed, you can then also grab their user meta (gender and country) and output it. That way, you don’t need to add any data to individual posts or CPTs, it’s just attached to the user, and whenever any user data changes, it will refresh wherever it’s being displayed.
It really depends on your theme what files you’ll want to touch. In Twenty Sixteen, for example, the file /template-parts/biography.php is the one that shows the author’s name and a touch of postmeta. It wouldn’t be hard to add the gender and country to that, which would then affect anyplace that shows the author.