By default, blogger templates are not optimized for good search engine results on the major search engines. In order to be relevant on the internet you need to be visible on the search engines and one important thing they look out for is your title tag.
Every blog or website needs traffic or else what is your website there for? you may write good content or make your blog look really good but you also need to make the big guns of the internet have a unique title tag to your blog.
It is very essential to make it your own title. What I mean is that you need to make it unique because say your using a title tag similar to an established blog, then you are competing with that blog or website. I'm sure you do not wanna do that.
So get a unique title for your blog and added to that is some little tweaking you should do in order to optimize your title tag. First of all, let me show you how to give you blogger blog a title.

Log in to your blogger account. Go to Design >> Edit HTML


Then find this line of code:
<title><data:blog.pageTitle/></title>

Now replace that with this:

<b:if cond='data:blog.pageType == &quot;index&quot;'>
<title><data:blog.title/></title>
<b:else/>
<title><data:blog.pageName/> | <data:blog.title/></title>
</b:if>


In order to edit your blog title and description, head over to settings and on the Basic tab under Settings like in the picture below: