Jekyll’s generator engine also offers a built-in template for a base website: Minima. If you let Jekyll create a website based on Minima, the resulting website will be very simple. For sure, a website based on Minima cannot give you an idea of what static website generators can do. With the help of the J1 Theme, this is significantly different, and you will get a full-featured website.
However, it will take some time to benefit from the extended capabilities that J1 Theme offers. I recommend spending some minutes on the technical terms and components used by the J1 Theme. This knowledge will help a lot to manage your site.