How do I name contingent beneficiaries in my will when the only family I have is my husband?

My one and only next of kin is my Husband who will be the beneficiary in my will
that I have yet to contact counsel about. I know I will be asked for contingent heirs but there are none. And in the instance my Husband should predecease me, who will execute my last will and testament? I am 68 years old and at a complete loss as how to proceed. I would probably donate to charities??? but don't know how to go about this. How would I go about researching their organizations? Would I check my own self in to a continuing care facility or assisted living? I have no friends close enough to rely on and feel that I am all alone in this (which I am)! My Husband does have family but I have never met them so they are out of the question. I am groping for viable answers and is anyone else in this type of situation? Please help...