What do I need to know about being guardian of my senior father with dementia?

I recieved a call that my estranged father has become senial and he is in a hospital at the moment. A social worker called me and said I need to go out there so that they can ign guardianship to me? Does anyone know what the process is? Also what questions I should ask or what to expect? What do I do with all of his belongings like home, car, financial stuff? I am very nervous about this whole thing because I have never had to deal with anything like this before.