I bought it for low light too, I went through the same learning curve you seem to be going through. You still need light, P or A mode works at f1/4, check the picture in A mode and adjust to f1.8 or f2.8. The trick for me was useing a manual tempeture setting of 3200 to 2800 indoors and turning on a few extra lights, working with the focus and using manual focus if needed to bring in their faces to a sharpness I liked. Work at it and you'll be happy once you learn it's limits and take pictures with in.
