Help my dad fighter cancer

Hello my name is Chris Garcia and my dad and my family really needs help. I am not sure where to start. We learned a week ago my dad Manuel Davila has advanced cancer. He has it in his prostate, liver and it has spread to his bones what doctors call metastatic bone disease. He went to his doctor regularly as he had a stoke last October. He complained of pain in his back and hip all year and his incompetent doctor said it was "old age" developing arthritis. My mom finally got a second opinion an MRI and CT Scan was done that is when cancer was found. We were all in shock, in a state of disbelief and devastated.