What are the formatting used for the newsletter in a word processor?

They can use almost any kind of formatting. Typically paragraphs use are fully justified. Headlines are generally centred. There are a wide variety of text sizes and sometimes colour varies. Different fonts are used. Special formatting to allow pictures and enable text to wrap around it are used. It is really down to the person who designing it. Some people will want to do their newsletter in a different style to someone else and so they will use different formatting. Some may keep it simple, and others may want a more complex version.