You can control how your store looks and feels via the Website → Design section in your Ecwid admin. Choose whatever size images, product card layout, category name position, and many more you want. Once you update the settings this would be immediately reflected on the store within your website.
Spend some time here to make your store look just the way you wanted.
For Instant Site users
If you use the Ecwid Instant site for your website, in your Ecwid admin go to Website → Store appearance → Edit to make style changes not only for your storefront but also for the site. Here you can pick a theme, change the store name, the web address for your website, or even connect your own domain, and more.
Learn more in these help articles: