New to comp. Starting with NU because it's so diverse. No idea what I'm doing. Please help ;_;

Val Hallen (Ampharos) (M) @ Choice Specs
Trait: Static
EVs: 252 SAtk / 252 HP / 4 SDef
Modest Nature
- Volt Switch
- Thunderbolt
- Focus Blast
- Hidden Power [Fire]

Reginald (Scolipede) (M) @ Salac Berry
Trait: Quick Feet
Shiny: Yes
EVs: 252 Spd / 252 Atk / 4 HP
Jolly Nature
- Rock Slide
- Earthquake
- Megahorn
- Swords Dance

X-Ray (Muk) (M) @ Leftovers
Trait: Sticky Hold
EVs: 4 HP / 4 Atk / 248 SDef
Careful Nature
- Curse
- Payback
- Rest
- Sleep Talk

Judith (Tangela) (F) @ Eviolite
Trait: Regenerator
EVs: 248 HP / 216 Def / 44 Spd
Bold Nature
- Leech Seed
- Giga Drain
- Sleep Powder
- Hidden Power [Ice]

Chow (Braviary) (M) @ Life Orb
Trait: Defiant
EVs: 4 HP / 252 Atk
Adamant Nature
IVs: 30 Atk / 30 Def
- Roost
- Brave Bird
- Return
- U-turn

Jack (Samurott) (M) @ Leftovers
Trait: Torrent
EVs: 252 HP / 4 Def / 252 SAtk
Quiet Nature
- Hydro Pump
- Aqua Jet
- Ice Beam
- Megahorn