There is no option to rename a blogger page as like any file name in OS... But then ..how?
There is a simple trick to do that..
By default, blogger takes the name of the page from first line of the content. So.. here, technically, we aren't renaming the file rather we are creating new page with file name by following the below steps.
Step 1: Create a new page under blogger.
Step 2: Type a desired name on the first row that you want to name the page. ( Important step)
Step 3: Save and Publish