ShoreOak

I would second this. In fact the only 3 lenses I own are the 23 1.4, 56 1.2 and 10-24, and the first two are used the most. The only downside to the 56 is that it's not the fastest lens in terms of AF but still more than capable, and produces stunning images. For me it's a no brainer to pair with the 23mm

Hi Shooting in low light can certainly be challenging, but the XT-30 ( as with all Fuji cameras ) is more than capable when shot correctly. If you're using the kit lens and shooting handheld then you may not be able to have a long enough shutter speed in order to expose the image correctly which then means a higher ISO ( more grain). The 35mm F2 would make definitely make a difference in some situations as it allows more light to enter when used at F2 but I think the more important thing personally is to work on technique and understand what contributes to the final image. Have you tried using a tripod? That would be a real help with lower light situations.