You are limited by the dynamic range of the cheap 12-bit camera. I.e., the noise is relatively large compared to the stars.
(1) For short exposures, you can reduce the read noise (without hurting the dynamic range) by invoking the high conversion gain (HCG - check the Sony documentation) mode. In the case of the ASI482, that means using a gain of 80 (or more). ZWO does not have a way to explicitly turn on the HGC mode, and hijacks a specific gain threshold to turn HCG on -- in the case of your camera, that happens at a gain of 80. Also, in the case of your camera, it should reduce the read noise by about 9 decibels.
(2) Long exposures are dominated by dark current noise; you can remove the static part of the noise (sensor defects) by calibrating them out using dark frames that are taken at the same temperature and exposure duration and gain. In your case, it might be difficult, since the sensor temperature is not controllable. This dark current noise can be reduced by cooling your camera.
(3) The rest of the noise (random shot noise) is removed by stacking your light frames. Each time you double the number of frames, the SNR improves by 3 decibels. Stacking 8 frames will for example be about the same read noise reduction as turning on HCG. Proper stacking also increases the dynamic range.
So those are three things you can do to help. The first two are quick and easy, but is limited in how much you can do. Stacking will keep reducing the noise the more frames you use, and limited only by your patience.
Chen