How can I add a fixed image above the header?

That should be eminently do-able via a custom header.php template file in the child theme. You could add your new logo markup after <div id="page" class="hfeed"> and before <header id="branding" role="banner">. The rest is just down to some new CSS.

all you have to add is image url ( please upload that image into your server ) above header portion in index.php

Thanks I wil try it out!! ??

Esmi How would i do that?

@ techblog I tried but was not successful. Nothing happened.

By editing your child theme’s header.php template file.

i added it with a img url …. thanks.