Can I work with expo with out knowing react native am coming from python
Of course!
JavaScript is a pretty easy language to get started with. Start with our docs, the react-native docs, and http://es6katas.org/ (to learn JavaScript).
You can, but its always good to know fundamentals
I know javascript, but can I build an app without knowing react native.
Expo uses React Native and JavaScript so when making an Expo app you’ll have to learn both.