To get learn from beggining from xml codes you can check my first post here on blogger design series i.e xml codes declaration.
First i request you to please create a new demo blog with any name in your blogger account and choose a minima template (First template in Template Lists By Google) as its layout to learn the tutorials.
Then got To Its Layout > Edit Html.And now check for below two lines in codes.
Now i will tell you something about head tag and how to add meta tags.
The head element is a container for all the head elements. Elements inside can include scripts, instruct the browser where to find style sheets, provide meta information, and more.
The following tags can be added to the head section: