Maker - Header, navigation and footer
Header - Logo
You can set the size of your logo using the Custom logo height range slider. Logos 50px and below will display inline and will be constrained within the header. Logos above 50px will overflow over the header and sit above content.
Inline logos 50px and below
Overflowing logos - 50px and above
Menus can be added and edited in your store admin under Online Store > Navigation.
Below shows two example menus for your store's Main Menu and Footer.
Create a single dropdown menu
Create a multi-column dropdown menus
You can create drop-down menus up to three levels deep.
To create third level menu items, repeat the process for creating a dropdown and simply nest them below a second level menu item.
If a second level menu items doesn't have any nested menus, they will be styled in a separate column shown below with New in and Sale.
You can add a horizontal menu to your footer by creating a menu in your Navigation section with the handle "Footer".
If you want to remove the "Powered by Shopify" - you can follow Shopify's instructions