Handful of newbie questions (Drupal version, admin language change, adding user…)

Hello to everyone.

Thank you so much in advance for your patience with a complete newbie. My situation is as follows – we started working with a new client whose websites are running on Drupal, which nobody in our agency has any experience with (unlike WordPress or Joomla). Not only do we know nothing about it but we also found out the administartion is in German.

It looks like this: https://www.screencast.com/t/V8BSZ5kX3j

My questions:

1) How do I fully switch the admin (and only admin) to English without affecting the websites’ content?

2) How do I add another admin user and set-up their permissions/roles? I can’t seem to find it anywehere… (Maybe I don’t have admin access even though it’s the client’s account?)

3) How do I learn the actual Drupal version that is being used and modules installed?

Your help will be appreciated…

Source: https://www.drupal.org/taxonomy/term/20/feed