Access: Settings > General > General Tab

Meta Keyword & description are for search engine used.
Search engine will categorize your website based on the keyword,when user searching in search engine your website might able appear in the list.
If your keyword are too common,then your page rank is competitive.You need to compete with other websites that used same keyword.

Page Title define the title of a website.

 

Optimal Format
Primary Keyword – Secondary Keyword | Brand Name
or
Brand Name | Primary Keyword and Secondary Keyword

 

Best Practices: Less than 70 characters, as this is the limit Google displays in search results.

Page title is the single most important on-page SEO element (behind overall content) and appears in three key places:

  1. Browser
    Title Tags show up in both the top of a browsers chrome and in applicable tabs.keywords2
  2. Search Result
    Pages Title tags also show up in search engine results.
    keywords3
  3. External Websites
    Many times, external websites (especially social media sites) will use the title of a web page as its link anchor text.keywords4

Just fill in your page title,meta keyword & meta description at Setting > General > General tab > title,meta keywords , meta description column:

keywords