[S/M] Advice on Nature etc on this team?

[Fana]

This is the team I'm planning on using, I do wanna play some Competitive modes. So all the help is welcome to be honest!

Charizard Y @ (Held Item)
Ability: 
Level: 100
EVs: 
Nature:
IVs: 
-
-
-
-

Venusaur @ (Held Item)
Ability: 
Level: 100
EVs: 
Nature:
IVs: 
-
-
-
-

Blastoise @ (Held Item)
Ability: 
Level: 100
EVs: 
Nature:
IVs: 
-
-
-
-

Tapu Lele @ Choice Scarf  
Ability: Psychic Surge  
Level: 100
EVs: 12 HP / 4 Def / 236 SpA / 4 SpD / 252 Spe  
Modest Nature  
IVs: 0 Atk  
- Psychic  
- Moonblast  
- Dazzling Gleam  
- Thunderbolt

Tapu Koko @ Life Orb
Ability: Electric Surge
Level: 100
EVs: 252 SpA / 4 SpD / 252 Spe  
IVs: 0 Atk / 30 Def  
Timid Nature
- Dazzling Gleam
- Thunderbolt
- Volt Switch
- Protect

Garchomp @ Focus Sash
Ability: Rough Skin
Level: 100
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Earthquake
- Dragon Claw
- Poison Jab
- Protect

What do you guys advice on the first 3? Honestly have no clue.

Thank you for anyone willing to help me!