Simple! Beat all the gyms!
getting symbols?
No i dont think so
Your Trainer Card will change color.
no you can not
complete the pokedex, catch every Pokemon get all badges and symbols gold and silver then you hav beaten the game
you have to get these symbols it's fun but hard
Talk to Scott to receive a special berry.
get all the Pokemon in the emerald dex
if you fully beat it (all 7 gold symbols) and talk to scott he will give you a starf berry
emerald has all the Pokemon
Each star represents a accomplishment you have achieved, the following acommplishments will give you more stars: Beat the elite four, get all the hoenn pokemon, get all the johto pokemon, get all the kanto pokemon, get all the symbols.
You cannot get all 202 Pokemon just on emerald because there are Pokemon that are only obtainable in either Sapphire or emerald, but when you trade on emerald it will update your pokedex to national mode.