[Grammar] Anyone vs someone

What is the correct variant of asking :

Would anyone help me? or Would someone help me? and Why?

Thank you so much for your anwers and comments

Neither is either correct or incorrect. They are both correct, in context.

'Can somebody help me?' = Out of all the people who hear this, I need help from somebody.
'Can somebody help me?' = I've already asked once. There must be somebody who can help; are you really going to ignore my need?
'Can anybody help me?' = I really need help, and I'm not choosy about who offers it/

You can mix these together: 'Can somebody help?... Somebody?...Anybody?' (The "..." are pauses - not just me not being bothered to fill in the rest of the question! ;-))

b

I think, somebody is used when we expect an affirmative answer
and anybody is used when we expect a negative answer.
So both can be used according to the context.