New to Ghost, theme recommendations?

Hello, I’m new to Ghost, and I want to start a website/blog with various content such as recipes with different options like vegetarian, gluten-free, etc., or travel, places, and experiences. I’m not sure whether it’s worth buying a theme or not. I’ve seen some that have good aesthetics, but in terms of features like sidebars with widgets for sections or ads, customization at the post or category page level, or other features, they seem to be quite limited.

I’ve come across some theme creators like fueko (riero, nurui, etc.), brightthemes, or electronthemes that have some interesting things, but I’m not sure if it’s really worth paying for a theme and then if I edit some code or add widgets or other elements, I might encounter problems.

Can anyone advise me on a theme with many customization options and features? Or is it really worth buying one, or should I start with the official Ghost theme (source or casper) and customize it later?