I'm not sure what I need to have in place to obtain POA or guardianship. Any advice?

Hello my sister was diagnosed last year with stage 4 glioblastoma brain cancer. She had surgery to have it removed and it has returned. My mother is 73 and can’t handle all the tasks that have been occurring like making drs appointments, dealing with bills and now recently she was evicted. Although she has 2 grown sons who should be helping out they aren’t. What is it I need to have in place to be able to deal with all this stuff without running into hassles. I have had people ask me if I have power of attorney and now today I had someone ask me if I have guardianship. I live 2 hours away and I can’t drive to where she lives every time there are things to deal with this. Because its becoming everyday