Help on my offensive andstorm team.

Keep in mind this is my first competitjve team, so go easy on me. Thanks

1. Tyranitar. Adamant. EV's = 252atk 252spd 4HP
Sand Stream
Crunch
Superpower
Stone Edge
Earthquake
~Expert Belt

2. Flygon. Adamant. EV's = 252atk 252spd 4HP
Levitate
Fly (idk why)
U-Turn
Earthquake
Outrage
~ Choice Scarf

3. Lucario. Adamant. EV's = 252atk 252def 4HP
Inner Focus
Close Combat
ExtremeSpeed
Ice Punch
Swords Dance
~Life Orb

4. Rotom-W. Timid. EV's = 252sp.atk 252spd 4HP
Levitate
Thunder Wave
Thunder
Volt Switch
Hydro Pump
~Choice Specs

5. Mamoswine. Adamant. EV's = 252spd 252atk 4HP
Snow Cloak
Superpower
Ice Shard
Earthquake
Ice Fang
~Leftovers

6.Metagross. Adamant. EV's = 252atk 252HP 4Def
Clear Body
Stealth Rock
Hammer Arm
Meteor Mash
Zen Headbutt
~Quick Claw

So yeah. Thats my team. Tell me any thoughts or whatever. Thancks. c:

Normally, I'd make Tyranitar a setter-upper of Stealth Rock, but since Metagross is already carrying it, a Choice set might be better:
-Crunch
-Pursuit
-Stone Edge
-Superpower
Nature: Adamant/Jolly
EVs: 180 HP/252 Atk/76 Spe (Adamant) or 4 HP/252 Atk/252 Spe (Jolly)
Item: Choice Band (Adamant)/Choice Scarf (Jolly)
Ability: Sand Stream

While Flygon is a good scout/revenge killer with U-turn + Choice Scarf, it doesn't have much power. IMO, Scizor is a better alternative:
-U-turn
-Bullet Punch
-Superpower
-Pursuit/Quick Attack
Nature: Adamant
EVs: 248 HP/252 Atk/8 Spe
Item: Choice Band
Ability: Technician

Running Thunder on a sand team is a big no-no, since its accuracy will be cut to 50% in sandstorm. Rotom-W lacks reliable recovery outside of Rest and Pain Split, so the latter attack is preferred over Thunder. And it seems you're using a defense-oriented set, so the preferred nature and EV spread are Calm with 248 HP/28 SAtk/232 SDef, and the item should be Leftovers. And as an alternative, if you want to keep your current spread, Thunder Wave isn't the best option in a Choice set, since you'll be locked into the move after use unless you switch out. Replace it with Trick so that Rotom-W can cripple walls and physical attackers with its Choice item. Also, replace Thunder with Thunderbolt or Hidden Power (Ice).

Since this is a competitive team, Icicle Crash is still preferred over Ice Fang on Mamoswine; you can breed female Swinub/Piloswine/Mamoswine with a male Beartic with the move. Thick Fat is also Mamo's preferred ability to give it a neutrality to Fire and a resistance to Ice. I'd put Terrakion in its place since it benefits from the 1.5x Special Defense boost in Sandstorm:
-Swords Dance
-Rock Polish/Substitute
-Close Combat
-Stone Edge
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb/Air Balloon/Salac Berry

Metagross should use Pursuit over Zen Headbutt, as Pursuit has more utility in catching fleeing opponents, especially Ghosts/Psychics. The EV spread should be 252 HP/96 Atk/160 SDef to help it take special hits more easily.