Um, I am not certain that discontinued phone from 2012 can even connect to get the flash player.
Is this the phone?
This is the equivelant of a flip phone! Even if it did connect to a "store", it wouldnt have the MEMORY to HOLD the app, as the specifications read as:
10 MB, 64 MB ROM, 32 MB RAM
FLash lite specifications:
128KB of RAM (2MB recommended)
So, how many apps are you running? Close some apps!