I need help with Master Yii and i need help choosing with shop

istg whenever i play master yii, i always get wrecked fast. I dont know what upgrades in the shop to choose. My strat is to target enemy minions untill i reach level 6 and then target other champions + towers/turrets I heard it was a good strat but i still cant get it done. pls help

I don't know, I don't main Yi, but a lot of times i see Yi mains use Duskblade as the first item - the rest really differ. Some of them use the Rageblade.