I'll take a stab at understanding you:
You find the fundamental object-oriented concepts difficult to understand, particularly inheritance (how a derived class automatically inherits members and methods from its parent class, and only new or changed functionality needs to be specified) and exceptions (a way of propagating error conditions back to the first caller in the chain with code that "catches" that exception, outside the normal function call stack). Am I close?
As far as gaining a better understanding of these concepts, if you can understand what I wrote above, then the next step is to clearly formulate a question regarding more specifically exactly what part of the concepts continue to cause you confusion.
All smart-assery aside, we really are here to help, but we're not going to teach you a course in "essential object-oriented concepts" for free.