How to put catagories in a seperate page?

I’d suggest starting with Category Templates to get a feel what you can accomplish with Templates.

I tried that arc-cont page code.

However when I open the page I get this:

atal error: Call to undefined function: get_header() in /home/httpd/vhosts/marginalwalker.co.uk/httpdocs/wp-content/themes/equix/arc-cont.php on line 7

Whats wrong?;)

You should never access directly any template file.
If it is a Page template (and according to the Codex it is) you should always create a Page in the admnin panel using that special template and then try to see the Page.

This is what I get now.

https://www.marginalwalker.co.uk/?page_id=32

You don’t put the code in the Page, like when Write > Write Page.
You edit the .php file in a text editor and after uploading it into your theme folder, go admin > Write > Write Page etc.

A big thanks! ??