First up welcome gtlogy to the forum. There are three factors that affect the amount of light getting into the camera so when the available light is low you can try:
(a) use a lens with a lower f number/aperture. eg the Panasonic 20mm f/1.7 is the 'fastest' native lens;
(b) use a longer/slower shutter speed but unfortunately this can cause blurring due to camera shake; and
(c) raise the ISO or sensitivity of the sensor although this will make the photo 'noisier'.
The final choice will always be a trade-off between these 3 factors. As Armando said sharing some pics with us and giving the exposure settings you (or the camera in auto mode) chose will allow us to give more specific feedback.
Finally a tripod will allow you to user slower shutter speeds with minimal camera shake.