If I call the social security office in Redding can I ask them to request my son's social security number

Ssa can never read you a social over the phone but if you bring an Id for a child you could request a replacement card or a print out. You could use shot records, student Id, medical record or passport. There are more forms but those are most common.

If he is a minor, yes. If he is an adult, he will need to do it himself.

Yes you can