please help with my team!!!

[Gero's-rookie]

ok well to start of this thread i am gero's-rookie and i need some help with my game.

btw it's pokemon leafgreen so yea. can you please help with natures, move sets and where to ev train for my pokemon, i haven't ev trained yet but i am hoping to.

ok heres my team:

nidoking, lonely nature/ holding nothing.
moves:
blizzard ( will swap for ice beam)
double kick
mega horn
thrash

mr. mime, timid nature/ holding nothing
magical leaf( just needed somehting to kill water pokemon)
pysbeam
psychic
barrier

dodrio, serious nature/ holding nothing ( should i swap with pidgeot?)
fly ( just to get aroudn to places)
drill peck
aerial ace
tri attack

sneasal, serious nature/ holding nothing
faitn attack
quick attack
screech
agility

octillery, adamant nature/ holding nothing ( should i swap to golduck because goldduck is my favourite pokemon)
surf
bubblebeam
psybeam
aurora beam

filler. i was thinking of putting a machamp, gengar, arcaine/houndoom, raichu or vilepume

so what do you's think???