CS50 is not the same course as introductory C course, so you have some more advantages than just having a live conversation. It is hard to advice anything without knowing what topics are you going to show on 24 sessions, how many students are there in classroon and with living far from US therefore not knowing anything about your culture.

Probably one of decent ideas is to implement a version control system early, so the student is going to have a working one before the code becomes too hard for one person without even a version control system. In my studentship we used to write text editors and we used to learn a lot about bits and bytes and some big old computers but what matters more IMO is all kinds of free and open-source tooling for text.

I would say, make it practical, with some live coding and incremental building of something they can use and play with.

C is a great language, especially for teaching CS (python is too but C allow to get into memory allocation and all the fun part of what make computing and compiling fun.)

I have learn C with code writing on a black board and pen and paper... that was good too but not sure if young people would have enough patience for such an approach