Questions about Blocks and Menus
A menu is not a block, it's just a collection of links... but the core menu module from Drupal renders the menu as a block to be easier for you to place it in the page and change its location.
There are multiple ways to export or import a menu. Yes, features module is one of them, but for a beginner I would suggest a module only for this, it should be easier. You can try this module.