Dude , I really need your help! I've won some battles ,but the people that I 
lose to are hard ,and Iwant to show them that I can beat them.So will you 
please help me !!!! Oh , I wanted to tell you that I want my deck to have a 
stronger defense and make my opponents unable to attack. Before I forget my 
deck is called Rocket's Aquatic Punch. I guess I'll show you my cards.


ENERGY:
x14 water energy
x13 fighting energy

POK'EMON:
x1 Blastoise
x2 Squirtle
x1 Wartortle
x1 Dark Wartortle
x2 Seel
x1 Dewgong
x1 Poliwag 
x1 Poliwhirl
x1 Oinix
x2 Geodude
x1 Graveler 
x1 Golem
x1 Rocket's Hitmonchan

TRAINER:
x3 Super Potion
x2 Bill
x2 Prof. Oak
x1 Pok'e. Breeder
x1 Pok'e. Trader
x2 Energy Search
x1 Revive
x1 PlusPower
x1 Defender
x1 Brock
x2 Energy Removal

There's my deck ,Rocket's Aquatic Punch , please fix my deck if theres any 
prooblems with it.

                                     Sincerely,
                                                  I really need your help boy
Looks like you've settled down on a water-fighting theme for this deck. Let's take a look at what you are trying to do with it. It looks like you have Blastoise, an excellent choice, the Dewgong family, and the Poliwhirl family in water. I would recommend ditching the Poliwhirl family in favor of increasing your Blastoise and Dewgong family card counts. For fighting, you have Onix, Golem, and Rocket Hitmonchan. A better choice might be Hitmonchan here, if you have any. You also might consider dropping fighting altogether and go with a pure water deck, Wooper is an excellent water pokemon with his lightning resistance. Alone he can take out a Magmar on the first turn with a little luck! Impressive! And against the big Electabuzz, there is a 50/50 chance that his most powerful attack hurts you or your opponent... essentially rendering him useless too!

Let's assume you can trade for or have some Hitmonchans. If you absolutely can't get them, you can substitute Machops until you can get them. I'm also adding 1 more Blastoise to your deck, so you can better make use of his awesome power.

Pokemon (14 Basic + 6 Evolves = 20 Total):
4 Squirtle (Team Rocket)
2 Wartortle
2 Blastoise
3 Seel
2 Dewgong
3 Wooper
4 Hitmonchan

For energy, we need a little Fighting, a lot of water, and some DCEs for the Woopers. We'll try to keep this deck using as little of Neo as possible, since it doesn't look like you have a lot of it yet.

Energy (19 Basic + 4 DCE = 23 Total):
7 Fighting
12 Water
4 Double Colorless Energy

For trainers, we don't have a lot like most tournamet decks... but I don't want to overload you with them since you aren't used to playing with a lot of them just yet. Eventually, as you become an even better player, you'll want to trim back your Pokemon and Energy count to as little as possible and fill your deck with upwards of 30 trainers or better! For now, we'll just put in the 17 that you have room for.

The most important thing for trainers is card drawing. Every deck needs a little bit of this or else it just doesn't work well. After you select the cards you want to use for card drawing needs, then fill the deck with things that either support the theme of your deck (Blastoise) or disrupt your opponent (Energy Removal/Gust of Wind/Stadiums/etc.).

Trainers (17 Total):
4 Bill
3 Professor Oak
2 Computer Search
2 Pokemon Breeder
2 Sprout Tower
2 Nightly Garbage Run
2 Gust of Wind

Good luck as you play this deck and make it better in the future!