You can trade in early but you are not strong enough to handle someone in 1v1 in early game.So you should farm a lot in early because it is very easy as Corki since your Q+R combo kills the mage minions. In late try to make cathces with your packet and roam a lot to help other lanes and collect some kills/assists.

Personally i recommend to use Barrier and Flash but if you are confident enough teleport would do the work too.

Well guys i am not a huge corki player this season since the nerfs but beofre that i used to play a lot as him. Nowdays he is becoming better and better thanks to the item changes and i feel like this is the time for him to come back to the meta as a hybrid mid lane carry. I couldnt put him into any team role so i chose other because he is not ad or ap or assassin he is just a mid lane hypercarry who uses both magic and physical damage as his adavantage.

Pros: High damage outpot from a far in late. Good mobility.
Cons: Low damage output in early game. Squishy if you don't have W in early you are 99% dead if the enemy jungler ganks.