Having my first supervision soon, but I have nothing to tell or even ask
I would guess that your supervisor simply wants to stay in touch, in general. I am in mathematics, but/and in early stages and even during their thesis-writing, my students often have said that they have no coherent questions, nothing to show, etc. In recent years I've attempted to more forcefully make the point that our weekly meetings are not at all necessarily about "good questions" (in math, the usual joke is that to be able to ask a good question is often more difficult than proving a good theorem...) nor about "progress". Rather, it's to stay in touch, chat about the project and related matters. Often, by-the-way questions come to light, often disclaimed as "dumb", but these are really the only questions anyone every has, and mostly I can answer them.

In a subtler way, "chatting" about things related to your project, or even only very distantly related, helps your advisor get to know you in that context. Very-experienced people can make a lot of high-likelihood inferences from details of casual technical conversation.

Also, there's the pep-talk aspect. Assuming things are going even approximately alright, your advisor has that opportunity to encourage you, or reassure you, etc. For that matter, especially later, it may become rather difficult for you to see whether you're making good progress, or not. After all, you've not written sooooo many theses? In contrast, presumably your advisor has seen many examples, and can reassure you that, yes, everything really does take this long, even when one works very hard.