It means that you need some help and you are asking someone for it

"to give a hand" = "to help" "Could you give me a hand?" = "Could you help me?" However, in another context, "give a hand" means "to applaud." Example: "At the end of the song, the audience gave the singer a hand." = the audience applauded the singer.

It means 'Can you help me (with something)?' That suitcase looks heavy. Should I give you a hand taking it upstairs? I don't understand this homework. Would you mind giving me a hand with it?