Flash builder question

Alright this is hurting my feelings =/…

Honestly, before today I’ve never heard of flash profiler before, I did some googling and found out that it’s a nice tool that I might need for debugging/optimizing my app. Apparently this requires Flash Builder, so I downloaded the trial.

I must admit that I understand nothing about Flex/Flash Builder and this whole mxml/framework thing. I just want to use the profiler to optimize my application…
My question is, how to profile? I failed after a hundred tries >_<

Thanks