Hide your Sidebar on Mobile Globally

/* Hide your Sidebar on Mobile Globally */
@media (max-width: 767px) {
	.widget-area.sidebar-primary { display: none; }
}

You can also hide your sidebar on mobile devices per post:  Hide your Sidebar on Mobile per Post

http://docs.oceanwp.org/article/479-hide-your-sidebar-on-mobile-per-postAll CSS snippets should be added via a child theme's style.css file or using the built-in Custom CSS panel.