First convoy engagement advice

[jwolf4]

I was notified of a convoy so I intercepted it. I took account of the ships I saw and there were 2 corvettes, 1 destroyer, and tons of cargo ships. I've never seen so many ships at once before and I need advice what to do. Should I try to take out the destroyer up front and then cargo ships? Should I just shoot at cargo ships and run? Which cargo ships are the best to destroy? I saw some new ones that are really big. Some have cranes on them. Some have stacks of barrels (it looks like).

What do you think someone should do in this situation to score as many kills as possible and make it out alive? I have 7 torpedos left up front.

Thanks