filmic is quite simple, just ignore most of the sliders.
- use exposure to set the overall brightness, concentrating on midtones;
- set white and black points in filmic according to taste
- set the contrast to taste
With higher contrast, or unbalanced white/black relative exposure, the curve may clip. In that case, switch to the advanced tab, and set the contrast in shadows/highlights setting(s) to safe. - If you are not pleased with the colours, scroll through the preserve chrominance options. It only takes a few seconds.
- If still unhappy, try a different color science (one of v5 and v6 will most probably work well).
If this is till too complicated, try sigmoid. It has a contrast slider, one to shift contrast towards darker or lighter tones (skew), one color processing selector, and if you choose per channel as the color processing option, another slider that you drag to see if some setting gives you more pleasing colours.
If still unhappy, try base curve, possibly with a fusion setting. You can find a well set-up base curve in the XMP attached here: filmic v6 loss of contrast - #19 by Leniwiec. @Leniwiec swears by the base curve.
Or try some styles – but not from dtstyles.net, which is outdated.
A selection of Darktable Styles – One Camera One Lens
Editing Made Simple In Darktable. A Video. – One Camera One Lens