Hello,
what a nice cat...
"friends" in FPN, as I understand it, is some kind of bookmark for people, you want to keep contact with through their topics and posts because they are of special interest for you.
The "friends" I bookmarked are Germans (hard to find in Germany...

) or nice people I want to know about.
When I want to add "friends" I go to the button "members" on top. I search for the nickname and there is a point "add as friends" - click and done
FRIENDS are of the most important things in life. Whereever you can get them, even if it's in FPN, go for it
Best wishes from Germany
Anna