From your Shopify admin, click Online Store => Click Customize for the theme you want to customize => Click Theme Settings.
In Theme Settings tab. Click 404 PAGE Tab. You can configure 404 PAGE for your site.
App Integrations
You can manage App Integrations in Theme Settings tab.
You can Enable/Disable any section via config in Theme Settings => Cart tab.
You can manage Currency Code via config in Theme Settings => Currency Code tab.
You can manage Favicon via config in Theme Settings => Favicon tab.
Default Featured Image
You can upload the Default Featured Image feature to replace for element image that has no image
You can upload the Logo image in Theme Settings => Logo tab.
Newsletter popup
In Theme Settings tab. Click Newsletter popup Tab. You can configure Newsletter popup for your site.
Page Sidebar Menu
In Theme Settings tab. Click Page Sidebar Menu Tab. If you choose the menu for Page Sidebar Menu, on CMS Page will show it as a sidebar.
Payment Methods
In Payment Methods tab. Click Payment Methods Tab. You can configure Payment Methods for your site.
In Theme Settings tab. Click Products Tab. You can configure Products for your site.
In Theme Settings tab. Click Social media Tab. You can configure Social media for your site.
In Theme Settings tab. Click Checkout Tab. You can configure Checkout for your site.
In Theme Settings tab. Click Global Styles Tab. You can configure Global Styles (typograph, color..) for your site.