PMMP File Structure

Hi,
I am making a core for my server.
I am finding it difficult (sounds stupid) in making a new file. I always get confused in, creating classes, is there some sort of tutorial,

 

Is their a wiki?

 

Same I keep having problems registering a command or an event, always gives an error.

 

Yeah there isn’t much of a wiki for this, yet it’s one of the most IMPORTANT thing

 

what error