I have this section and, for layout proposes I would need two divs inside that section. Of of them, should wrap the header part of section.
So:
<section>
<div id="layout-stuff">
<header>
<h1>This is the section header</h1>
</header>
...
</div>
</section>
Is this ok?
Yes, you can do this. a
<div>is nothing more than an element to hook styles with.