Duplicate Meta Description and Titles Issues In Blogger

To add Meta Tag to your blog, refer to this post: Meta Tags - Importance and How To Use

Solution for the problems:
1. First of all, in the template (Blogger-> dashboard -> Layout -> Edit HTML) find (CTRL+F) the code for meta description tag, something like this:

<meta content="GENERAL_DESCRIPTION_HERE" name="description"/>

Now put that tag in an "if" condition, so that it will be displayed ONLY in the HOME PAGE:

<b:if cond='data:blog.url == data:blog.homepageUrl'>
<meta content="GENERAL_DESCRIPTION_HERE" name="description"/>
</b:if>

 2. For the second issue (duplicate titles); in the same page (Layout -> Edit HTML), click on "Expand Widget Templates".
Then find (CTRL+F) this code:

<a expr:href='data:comment.url' title='comment permalink'>
<data:comment.timestamp/>
</a>

 Replace the entire code with this new code:

<b:if cond='data:post.commentPagingRequired'>
<a expr:href='data:comment.url' title='comment permalink'> <data.comment.timestamp/> </a>
<b:else/>
<a expr:href='data:blog.url + &quot;#&quot; + data:comment.anchorName' title='comment permalink'> <data:comment.timestamp/> </a>
</b:if>