How to add html in an existing div class

Hi everyone,

I am trying to insert html in an existing div in my header.

I created a header.php file in my child theme and inserted what i want to show but it created a new div with the same clash instead of appending in it.

My website is https://www.cineflery.gr and what i m trying to do is to put the Facebook follow link in the Header with icon in the same spot where the wordpress follow links are. What should i do in order to append in an existing div class instead of creating another one when i am writing my code.

I want to append in <div class=”row-fluid”>

the links a href=”” title=”Visit Us On Facebook”

But now i have 2 <div class=”row-fluid”> instead of 1

Thanks