Hello
Edit this file /templates/ja_fixel/etc/assets.xml and change the http to https
<stylesheets>
<file>http://fonts.googleapis.com/css?family=Roboto:400</file>
<file>http://fonts.googleapis.com/css?family=Roboto:100</file>
<file>http://fonts.googleapis.com/css?family=Roboto:100italicc</file>
<file>http://fonts.googleapis.com/css?family=Roboto:300</file>
<file>http://fonts.googleapis.com/css?family=Roboto:300italic</file>
<file>http://fonts.googleapis.com/css?family=Roboto:400italic</file>
<file>http://fonts.googleapis.com/css?family=Roboto:500</file>
<file>http://fonts.googleapis.com/css?family=Roboto:700</file>
<file>http://fonts.googleapis.com/css?family=Roboto:500italic</file>
<file>http://fonts.googleapis.com/css?family=Roboto:700italic</file>
<file>http://fonts.googleapis.com/css?family=Roboto:900</file>
<file>http://fonts.googleapis.com/css?family=Roboto:900italic</file>
<file>fonts/novecentowide/stylesheet.css</file>
</stylesheets>
Regarding the 404 error it is a missing file somewhere you should add a logo.png image
Regards