First of all, you should not be editing any theme files directly. If the theme gets updated because of feature enhancements, bug fixes, or security patches, or if the theme has to be updated because of a change to the WordPress core, then your changes will be lost. Instead, either create a child theme or use a CSS plugin like Jetpack or Custom CSS Manager.
1. Is there way to change title (side bar on top) to be specific font style? ex: (Arial, Calibri or others)
As @eainnem inferred, you can add this overriding rule to either your child theme’s style.css file or by using a CSS plugin:
.blog-title a {
font-family: Arial,sans-serif;
}
2. Is it possible to add description under title?
You can do it the easy way or the hard way. The hard way is to create a child theme (if you haven’t already), and then modify a copy of the header.php file to add the description. If you are familiar with coding, it shouldn’t be too hard, you just want to look for the code that says:
<?php echo esc_attr( get_bloginfo( 'description' ) ); ?>
and duplicate it somewhere in the header.
The easy way is to add a CSS rule that looks like this:
.blog-title:after {
content: 'This is what my site is about';
display: block;
margin-top: 10px;
font-size: 15px;
color: red;
}
There are some limits as to the content. For example, you can’t include HTML tags. But you should be able to style it using additional properties, like the ones you see here.
3. Is there way to change specific page background color without affecting other pages?
Yes. This theme, like many properly constructed WordPress theme, calls the body_class function. What this function does is to add special class names to the <body> element of each page or post. What is pertinent to your question is something called the page/post ID. If you inspect a page on your site using a web debugger (like Firebug for Firefox or Chrome Developer Tools) and inspect the <body> element (or just do a view source on the page and look for the <body> element), you’ll see that the body has a class which looks like page-id-123 (for pages) or postid-456 for posts. The number at the end of each post or page ID will be unique for each page/post, so all you need to do to set the background color of a particular page is to include that class name in your selector:
html .page-id-123 {
background: red;
}
