api csv import - cannot find start page
you are correct, the page is civicrm/csvimporter/import 

(as defined here: https://github.com/eileenmcnaughton/nz.co.fuzion.csvimport/blob/master/xml/Menu/csvimport.xml)

Your error is something else, like not having a compatible civicrm version. Can you give more details on your configuration? what version of civicrm and what CMS do you use (drupal, wordpress or joomla)?