I'm new on here and there is are a few questions I have but I don't know how to open a new thread to begin one. Any advice?

Plus my hair is 3b/3c/4a type hair and I have always had low porosity hair. Ive been natural for 6yrs, yes 6yrs with no length to speak of, no healthy strands either. Since I've been researching I see that I haven't been taking care of my hair properly. But on top of have low porosity hair I'm trying to see how to tie it all together to get healthy hair. And while I'm trying to figure out what to do with mine, I'm also trying to figure what to do with my oldest girl. How old does she need to be to test her porosity level?