Uh, since when has anyone got to train 'good pokemon' over pokemon they WANT to train. If someone wants to use a Pidgeot, then they can, there's no law stating they must use a better pokemon.
Pikachu - 30
Thunder ??, Slam, Quick Attack
Butterfree - 25
Confusion, Teleport, Sleep Powder, Whirlwind
Pidgeotto - 22
Fly, Gust, Whirlwind, Quick Attack
Charmeleon - 27
Scratch, Rage, Ember, Cut
Wartortle - 22
Bubble, ice Beam, Water Gun, Skull Bash
Right, now I can actually read your team better (spaces and full stops, they're the future when you are writing. Consider looking into how they work).
You are greatly under-levelled, try to get your entire team to at least level 35. Then, you can concentrate on giving them better moves.
I assume you are playing Yellow, since you have all the starters in one game. In which case, Pikachu should have Thunder Bolt. It should also have Thunder wave (level 8, or it's TM45). You should consider Double Team also.
With Butterfree, you have two utterly useless mvoes, Teleport and Whirlwind. Neither do anything in battle, making Butterfree a waste of space. Fortunately, they are not HMs, so you can get rid of them. Butterfree learns Psybeam at level 31, so if you want to keep the Psychic TM for a future pokemon, this will have to do. I suggest buying Reflect from Celadon and teaching it this too.
Buy Reflect for Pidgeotto too, it evolves at level 36, so do that. It will also learn Wing ttack at 31, so get rid of Whirlwind again. Consider Double Team once more, this time in replacement of Gust.
I suggest Dig on Charmeleon (over rage, that's a horrid attack). By then it will have learnt Slash too. It evolves at Level 36, so you may as well do that too.
Lastly, Wartortle evolves at 36, so you should by then have 3 fully evolved pokemon on your team. It will learn Withdraw at level 31, which would be far more useful than Bubble at this stage. Before you fight Koga, get Surf from the Safari Zone, and Strength too. teach both of these to Blastoise, giving it a powerful Water attack, and a solid Normal attack too.
Then, when your team are all at the same high level, try fighting Koga again. Stock up on Potions, Revives and Antidotes. If you're still having problems, level up more by retracing your path and fighting every trainer you missed, then clear out Silph Co of the Rockets.