a) You need a faster lens, at least f/2.8 or shoot more pictures for stacking
b) Set the camera to ISO 640 (with higher values you have less dynamic range and less colors)
c) Set the camera to daylight white balance
What @Thomas_Do got out is probably the best you can get. For demosaicing VNG4 + one time color smoothing will already reduce the noise a log. So one denoise profiled should be enough to get rid of the rest.
The key to noise reduction is to stack multiple images. Additionally, you can use stacks of dark, flat and bias frames to remove different types of noise. At least the shooting of several light, dark and bias frames can be easily achieved.
Have a look at siril. The program is a little difficult to handle at first but there are good tutorials in the internet.