Alrighty, I'll be rating this.
To start of, I actually think that Mew EX will do great for your deck alongside Mewtwo EX. This will allow you to use any attacks, and utilise the Energies well. This will make the deck extremely Hard-Hitting and will require very few energies to set up go for the sweeping.
First of all, you only have three Pokemon lines, two of which are Stage two lines. This will make it tremendously difficult to get the Basic and Stage one Pokemon in your hand to play the strongest Stage two Pokemon. So for now, lets put four Rare Candies to help this problem. Also, I suggest putting a Sigilyph (3 of these). So that you can have a Basic in play while powering all the others up in the Bench.
Dustox and any Cascoon plus the Wurmple will benefit your deck greatly. Dustox can be used to troll the opponent and slowly wear them down every turn with Hazardous Scales and deal damage later as well. It has 130 HP making it great to tank out while attaching energies to others for later turns. Then This Shedinja will benefit your deck greatly as Cursed Drop is great to wear early game basics at the attach of one benefit.
All the other minor changes will be listed here:
Total Deck Cards: 60
Mewtwo EX (2x)
Mew EX (1x)
Total Pokemon: 19
13x Basic Psychic Energy
4x Special Double Colourless Energy
This Special Double Colourless Energy is for Mewtwo EX. This provides two energies in one card so that Mewtwo EX's X-Ball will do a lot of damage.
Total Energies: 17
4x Pokemon Catcher
4x Rescue Scarf
2x Giant Cape
1x Town Map
4x Plus Power
1x Gold Potion
Total Trainers/Supporters/Items: 24
Here is you total Deck fully modified. The four Double Colourless Energies will give Mewtwo EX a great way to sweep your battles with X-Ball. The Bouffalant is great to put up against EX's to tank and and attack them well too. This will give you the upper hand not only with Pokemon defeating but also with the Prize Cards. The Town Map is there top help you choose the best Prize Cards every time the opponents Pokemon are defeated.
Well, that's it. Hope I helped you. Overall this Deck was great and for a starting player like you, it was awesome.