my team-any suggestions

1.Torterra-brave
wood hammer
synthesis
stone edge
earthquake

2.Garchomp-adamant
earthquake
fire fang
iron head
dragon claw

3.Forretress-impish
gyro ball
stealth rock
explosion
toxic spikes

4.lucario-mild
aurora sphere
psychic
extremespeed
blaze kick

5.gengar-modest
shadow ball
focus blast
thunderbolt
sludge bomb

6.tyranitar-adamant
dark pulse
stone edge
dragon dance
brick break

This is a decent team... You can only tweek this team from experience... There are some moves I would remove like dark pulse from tyranitar, and somethings from lucario... but only experience can make you do better... Your moveset tells me you never used it in a wifi battle or very little experience with it... well keep testing your team and the answer to make your team better will come to you

I would suggest taking iron head off of garchomp, and replacing it with swords dance or dragon dance. A buffed garchomp is practically unstopable in any metagame.