fix a few bugs in react native app (read description first)

I already have learn languages app (react native android and iOS) and it's already launched but we hide it from stores till complete updates..
app is firebase nodjs version 12.0
and I want to make these few fixes and updates
- fix levels clickable
- fix register issue
- put continue button in choose your level screen.
- put text under screens icons (home – learn – academy – library – profile)
- change flags icons for country and languages and add change language to setting
- put monthly price instead of annual price in purchase screen.
- fix audio bug.
Timeline: 1-2 day