Job over 50

I have not worked in yrs. and was wondering how do I get into the workplace again. There are reasons I stopped one was my child whom has mental issues like Bipolar, Oppositional Defiant Disorder, etc. which made it difficult to keep a job. Even now that she is a young adult and living with a boyfriend and neither of them drive so if she needs to go to doctor I need to be able to take her. But I feel I need to work now at least part time doing something but do not know where to begin. So, can anyone help?