Ich habe kein Auto.
English: I do not have a car.
The 'Verneinung mit kein' is a way to make negative sentences in German. It means saying that there is not any of something, or that something does not exist.
Use 'kein' to say that something does not exist or you don't have something. It is used with nouns that do not have a definite article, or with nouns in general.
Ich habe kein Auto.
English: I do not have a car.
Er trinkt keine Milch.
English: He does not drink milk.
Wir haben keinen Hund.
English: We do not have a dog.
Sie hat keine Geschwister.
English: She has no siblings.
Gibt es keinen Kaffee mehr?
English: Is there no more coffee?