Will the ideas for each week be suggested, along with what language to code in? Or is it completely up to the participant what and when they want to make?

I think a well-defined plan that everyone follows would be more useful, since we won't waste a lot of time trying to think of ideas, and we'll be more likely to hit all the points. Plus, it'll keep everyone on the same page, allowing people to share resources while trying to set up and learn the platforms each week.