For the 1st gym?

Lvl 14 Charmander
Lvl 12 Pikachu
Lvl 12 Pidgey
Am I ready?

You're more than ready! I defeated Brock with

Charmander - 10
Butterfree - 10
Pidgey - 9

Each one of them pitched in.

Thanks! By the way... I caught a shiny lvl 4 weedle. But I don't know if i should get a butterfree or beedrill, or neither. Whats your opinion?

I don't know, either neither or Butterfree. It's because around VERMILLION CITY, I tend to put my Bug in the PC. The highest Bug I ever trained was a Heracross at lv 62. Anyway, since you have a shiny, try to train/use it. But it's your choice.

As long as has Metal Claw for a super-effective strike, you should be OK. The problem with starting with is that the first couple of Gyms are really tough without a Pokemon with a type advantage - especially the first one. It's worth it once you get to the fourth Gym, though.

Between and I'd have to say is the better Pokemon, but if you have a shiny , then by all means evolve it into and train it to a high level (as long as you think shiny looks good). That's what everyone does with their shiny Pokemon, right?
When I caught a shiny in my Sapphire game, I evolved it into and trained it up to level 81, despite the fact that I don't really think is such a good Pokemon...

Caught a Shiny Weedle? Evolve and use it, I say.

Or you could save before you battle him and turn off the game if you lose.

Nah, Everytime I lose, I beat the Geodude without a problem. It gives good EXP., and It'll be easier If I level up

Now, I'm at Silph Co. Am I ready?
Team:
Lvl 37 Charizard
Lvl 30 Pidgeotto
Lvl 29 Dugtrio
Lvl 30 Raichu
Lvl 30 Vaporeon
Lvl 25 Hitmonlee
Am I ready?

EDIT: Oops, sorry for double posting...

I don't think you need confirmation on whether or not you're ready every time.

if i were you i would try to get all of my pokemon to around level 30

Yeah, I really Don't think you need to ask, I never really trained before an event or a Gym, and I usually get through everything without a problem the first time, if not the firsdt than the second. of course, this doesn't apply to the Elite Four. But if I was you I'd just go ahead and try, and if you fail, you've just learned that much more.

And of course, it can be solved very simply by a) saving before you attempt it, at a location you can get back out of (IE, in the foyer of the Elite Four, instead of in the first room), and b) simply going back and trying it again (or leaving and leveling up more) if you don't make it through on that attempt.