A child theme allows you to change small aspects of your site’s appearance while preserving the look and functionality of your theme. In order to understand how child themes work, it is necessary to know how parent and child themes work together. Checkout here → Advanced Topic

Once you activate Twenty Twenty Two child theme, its properties will be inherited from its parent theme. If you want to modify certain files like header.php, footer.php, or functions.php, you can copy them from the parent theme and put them to the child theme at the same folder or file path.

Another thing you should know about Custom Block Patterns. It is very much important in Gutenberg editor. Use below functions to add custom block patterns in a custom categroy 👇
register_block_pattern_category()
register_block_pattern()