You can upload your Logo for online store and customize your Favicon.
Just click on Store > navigate to Design > select Branding > Logo
Header Logo: recommended size is 420x84 px.
Format: PNG, JPEG or GIF
File should be less than 5 MB
Favicon: recommended size is 260x260 px.
Format: PNG, JPEG or GIF
File should be less than 5 MB
You also can design the Logo style
Select Logo positioning - Left or Center
Select Navigation bar size - Small, Medium, Large
Also you can fix the header on scrolling.
Check out our guides for Card Styles and Online store colors.