Literally it means 'not I'.
You can say "Je n'ai pas" in French to mean "I don't have."
"Je ne comprends pas" means "I do not understand" in English.
non je ne sais pas = no, I don't know
I do not have
Je ne parle pas français (?) - I don't speak French
"je n'ai pas d'animal" means "I have no pet / no animal" in French.
"Non, je ne suis pas," means "No, I am not." in English.
"je ne veux pas mourir" means "I do not want to die".
Je ne sais pas means 'I don't know'.
In French, you would say "Je ne comprends pas" to mean "I do not understand."
remarks on "je ne pas de sour": there is no verb in that sentence, and sour is not a French word. I gather that you mean "je n'ai pas de sous" which means familiarly "I have no money"
You can say "Je ne pense pas" in French to mean "I don't think so."