Show category on static page

I do however want to show all posts in a specific category on a static page

first step: make a page template;
which you could do by copying index.php and saving it under a name ‘gallery_page_template.php’ for instance.
https://codex.www.ads-software.com/Pages#Page_Templates

make sure to add this code at the beginning of this file:

<?php
/*
Template Name: Gallery Page Template
*/
?>

then go to ‘admin’ ‘page, add new’ – enter the page title you want to see in your menu, go to the right a bit down ‘attributes’ ‘template’ and choose your gallery page template form the list.

edit your gallery page template file, and add something like this before the loop:
<?php query_posts('cat=13&posts_per_page=-1'); ?>
(with your category id instead of 13)
(you can also use the category name – see docu)
https://codex.www.ads-software.com/Template_Tags/query_posts
https://codex.www.ads-software.com/Template_Tags/query_posts#Category_Parameters

this should be all.

Thank you very much..

I do not have a “template” option in the attributes – is that due to the fact that I have not made more than one yet??

Re-activated the theme, and it came up.. ??