Could you specify do you want to place this text globally through the site or only on the home page? If globally so you can place it to the header.php file. If only for the home page just add it via Visual Composer in admin panel -> Pages.
In this case you can edit header.php. file (we suggest you to override it in the child theme, just copy it to the basel child folder and open for editing). Then add your text directly after the header section and it will be shown on all page through the site.