Start by making mockups in Balsamiq. Then pick a single screen/view of your mockups to start picking up the basics of React Native (just use the Expo framework (which is a React Native framework) for rapid prototyping).
React is hard until your understanding of it finally 'clicks' - and having a wireframed visual reference of what your app is supposed to look like actually makes it easier to think about how it should be layed out in code, imo.
I actually just started learning React Native and I re-wrote the first iteration of my app's home screen many times (and kind of aimlessly) until I had something that actually made sense and was easily maintainable - still re-factoring it into something even simpler, tbh. That said, I think that was mainly due to me not knowing what was in the library or having approached the UI components properly in the first place, so I think I will be prototyping quite a bit faster over time.
re: state management/backend, I'm also confused as to what stack would be best for what I want to do. I'm guessing Firebase with some minimal manual state management? All the state updates my app needs to do is essentially record the user ticking some checkboxes, and some timers updating in the UI, and those persisting on a user's phone but also optionally associated with their account online if they so choose.
React is hard until your understanding of it finally 'clicks' - and having a wireframed visual reference of what your app is supposed to look like actually makes it easier to think about how it should be layed out in code, imo.
I actually just started learning React Native and I re-wrote the first iteration of my app's home screen many times (and kind of aimlessly) until I had something that actually made sense and was easily maintainable - still re-factoring it into something even simpler, tbh. That said, I think that was mainly due to me not knowing what was in the library or having approached the UI components properly in the first place, so I think I will be prototyping quite a bit faster over time.
re: state management/backend, I'm also confused as to what stack would be best for what I want to do. I'm guessing Firebase with some minimal manual state management? All the state updates my app needs to do is essentially record the user ticking some checkboxes, and some timers updating in the UI, and those persisting on a user's phone but also optionally associated with their account online if they so choose.
edit: I might actually go the PouchDB route