It does sound like you need to spend many hours reading the User Manual. Please do this – it really is the only way to learn how to use a sophisticated unit like the H8000.
One problem you may have is that the input is a Line Level input and is not suitable for a direct microphone connection – you will need to use some kind of Mike preamp between the mike and the H8000. Alternatively, it's also common to feed it from a mixing desk.
If you were sensible enough to get the unit from a good dealer, he will hopefully help you.