Started with squirtle

Right now im pushing
Warturtle
Garydos
Nidorino
Pikachu
(will get Dritini)

What should my before elite 4 top 6 and after beating elite 4 first time top 6
Preferably movesets with Pokemon and when i should stone my Pikachu/Nidorino

forum is a little dead to ask someone to do research. look up smogon, search by pokemon and leafgreen

you don't need gyrados if you have squirtle, try to get as many diff types as possible

for first timer going to elite four i ditched pikachu, got eevee and evolved that to jolteon (better than pikachu or raichu)

get a growlithe and evolve to arcanine after it learns flamethrower,

maybe try getting a strong haunter for bruno of elite four
strong ground type for agatha
and teach blastoise ice beam or ice punch for lance (i forget if it's learnable)

You Need Lightning Fire Ghost moves for First round
Second Round you need Water/grass/Psychic moves
Third Round you need Psychic/ground moves
For Lance you need Ice move ( Ice Beam Best Move )
And for Gary you should beat him easy with fully restored pokemons

Try...

Blastoise
Surf
Ice beam
Rain dance
Hydro cannon

Nidoking
Earthquake
Poison jab
Thunderbolt
Horn Drill

Lapras
Surf
Ice beam
Sheer cold
Perish song

Magneton
Thunderbolt
Thunder wave
Thunder
Thunder shock

Rhydon
Earthquake
Horn Drill
Rock slide
Swords dance, rock Polish

Exeggutor
Psychic
Giga drain
Sleep powder
Explosion