Setting up the menu differenly as default can be done with some CSS.
How to setup colors for your next Joomla4 website is explained here.
The article info, such as author, creation date, views etc, by default is displayed below each other.
KickstartCassiopeia has many features. You can choose to use all of them on all your pages, or for instance, use the popup on selected pages.
By default Cassiopeia had full width header and footer. This design option is widely used on websites.
KickstartCassiopeia enables you to use a mobile contact bar.