Can I easily export content? Let's say I have a Drupal 7 website, with 3 taxonomies and 3 articles.

 - Cars
   - Sport
     - Porshe
 - Family
   - Taurus
 - SUV
   - Navigator


No modules, no nothing, just this content and taxonomies.

Is is it a fairly simple process?
If you have nothing but that, yes, Drupal core migrate and migrate_drupal_ui module will easily do this.