Hey! Here are some examples:
Death: 'Drinking too much alcohol may cause death'; 'It is depressing to think about death'
Dead: 'He is dead'; 'She is dead'; 'dead body'
Die: 'I never want to die!'; 'I wish my cat did not die'
'Death' is a concept: the idea of dying. It can also be a noun: e.g. 'death will come'
'Dead' is an adjective, to describe a state of not being a alive.
'Die' is a verb, the action of dying.
Confusing, I know! But I think it will help to look at lots of different examples in context to get a better understanding!