Updates to existing Android App

I've currently got an app (which I took over from someone to begin learning, but just not got the time at the moment) which works in all versions of Android up to 10. Since the release of Android 11 some of the functionality doesn't work.

I also have a list of updates for phase 1 (see attached).

Its currently built in Java (Android Studio)

If working with the individual/team works out well then there is the potential for additional work as I've got 4 other apps that need work/updates