The SEO config file is located in the "src/config/seo.json" folder. In this file, you need to change the value of the field (title, description, etc...) or add some key-value that you need.
You can read all the options you can add here:
When you open the index page, you'll see cards (categories) in all kinds of colors. To customize your favourite color, go the the "src/config/card-colors.json" and edit the value follow by the key (category name) you need.
List of supported colors here : https://tailwindcss.com/docs/customizing-colors
The components are located in the "src/components" directory. You need to learn about React components to be able to edit the app properly.
Location: "src/components/Navbar.tsx".