Heres what you want to do, first off, you want to know Red's pokemon.
Pokemon Trainer Red $16800
Pikachu Lv. 88
Lapras / Lv. 80
Snorlax Lv. 82
Venusaur / Lv. 84
Charizard / Lv. 84
Blastoise Lv. 84
Now you want to counter all of them.
He starts with pikachu, so donphan will be of good use.
But you probally will want to level him up about 20 more levels. and You might want to ( this has nothing to do with beating red ) replace rollout with stone edge.
Well, thats his strongest pokemon down. or atleast his highest level pokemon.
Lapras: lv 80
Lapras is the lowest level of the team, but a pain in the butt. You're going to need a pokemon with high sp. def.
If you want to try to buff up you're arcanine then so be it.
Lapras is just... a pain in the butt. keep in mind pikachu is the only pokemon that you know when he's going to throw it out. the other pokemon come in a random order.
Well, get ready to die.
Your main chance agaisn't this thing is to find a focus sash, put it on your heracross, and murder.
thats all I can say, if you don't have a fighting type. You're as good as dead agaisn't this thing.
Venasaur: lv 84
Take out your arcanine.
Thats all I can say here.
Make sure to level up your pokemon still and on to...
Charizard: Lv. 84
Take vaporeon out. Make sure you move del. that whirlpool.
you can replace it with something else, like aqua ring ( don't judge me because I can't remember if vaporeon can learn it ) and just surf the crap out of his charizard. Its all ATK and SP ATK. It goes for the kill, quick claw on vaporeon might be good.
Blastoise: lv 84
Blastoise is a defender, with total offensive moveset.
meganium, with light screen.
After that you might be able to sneak in arcanine for a thunder fang. Or petal dance with meganium.
Hope this helps :D