@Kuro22: Context: I don’t know building apps.
If you don’t have experience building apps (in particular with React Native), it is more likely that you will encounter further difficulty understanding the project, its documentation, how to setup it up correctly, and how to deploy your own Lexicon-powered mobile app.
It is recommended you consult with someone that has familiarity with React Native, Expo, and general experience in NodeJS, as well as actually deploying apps to the App and Play Stores.
Also having a solid understanding of how .env files and environment variables work is vital to building and deploying this project on your own.
Without that, at best, you may be able to get it working locally. But trying to deploy it yourself without past technical experience may prove to be a frustrating experience without outside support.