Ecwid is an extensive and powerful e-commerce service. Itis easy to implement and it’s free to start off.
Here is a short video from the Ecwid youtube channel on setting up a shop. How to Create an Online Store in 5 Minutes! Ecwid Tutorial »
You can add custom CSS to your Ecwid shop to change fonts, colours and more. Here is a link to some examples.
Note: Ecwid offers paid plans. Make sure you don’t accidentally get charged.