Modifying format out checkout pages

-- HikaShop version -- : 4.0.0.
-- Joomla version -- : 3.8.12
-- PHP version -- : 7.0.30
-- Browser(s) name and version -- : Firefox

I am trying to set up a checkout process for my website ijscomanvenlo.nl.

First step is that customers can check out as GUEST and only give minimum necessary address information.

Enclosed you find 2 screenshots of the first checkout page and a screenshot of the checkout workflow setup.

I am trying to achieve a few changes, but I can't find answers in any documentation:
Where can I change the text "Gast"(just above the email)?
How can I remove "Country" and "State" from the adress?
Where can I change the text "Same address for shipping"?

Kind regards,

Hubert