I’ve seen a few different opinions on where to start with Zoë Sugg’s books, and honestly, it depends entirely on what kind of story you're after. If you're looking for her most iconic, published work that has a bit of a larger cultural footprint, then 'Girl Online' is the obvious entry point. It's a sweet, light-hearted YA rom-com about a blogger who goes to New York. It’s easy reading, and it’s what introduced most people to her as an author.
However, if you're already familiar with Zoë from her online presence and want something that feels more personally connected and contemporary, I'd actually suggest skipping ahead to 'The Magpie Society: One for Sorrow'. It’s a co-written mystery series, and I found the boarding school setting and the darker tone a more engaging hook than the 'Girl Online' plots, which can feel a bit dated now. It shows a different side of her writing interests.