Hi,

First, you should update the theme to the latest version. To update the theme to the latest version, please remove the code at the end of functions.php file like on this image: http://prntscr.com/uon4qx ( if you don't see it, you can ignore this step ) 

After that, do following this guide to get auto-updates the theme: https://pencidesign.ticksy.com/article/15633/

And you can upload favicon via Customize > General > General Settings > Upload Favicon.

Best Regards,

PenciDesign