How to fetch entries from multiple sections
You can insert an array of different sections instead of a single one to pull entries from multiple sections

{% set entries = craft.entries.section(['sectionHandle', 'sectionHandleTwo']).limit(10) %}


You can also write that

{% set entries = craft.entries({
  section: ['sectionHandle', 'sectionHandleTwo'],
  limit: 10
}) %}


If you remove the .section() / section:..., entirely you'll fetch all entries from all sections. 
Here's a link to the docs