After adding the logo homepage H1 disappear and no h1 all around website

This is governed by the theme. As you are using a commercial theme, you need to request support for this from your theme vendor: http://flexithemes.com/support/

Only people who own this theme will be able to help you as no one else will know how the theme has been built. I’ve added the ‘flexitheme’ tag to this topic in case anyone here does use it and knows how to correct the code, but the official line is that the WordPress.org forums are not meant to support commercial themes.