How would I properly light a nighttime scene?

So, I’m currently developing a small horror game purely just to learn about Unreal 4. I already did all the sky sphere stuff, and so far, I’m wondering how would I light an interior. I used the default lamp, and a flashlight light blueprint thing, but nothing is actually getting lit, besides the lamp and the other starter content that I used. I don’t know if it’s something to do with my materials, or with my imported map. This only happens after I build lighting, if I add a directional light, and give it the dark blue tint that I want, it’ll pretty much be exactly how I wanted it, except still lacking realism (as I am a beginner). So, the lighting only becomes weird, as I say after I build lighting

After that is resolved, I still don’t know how to properly light a night scene inside. I want to give it that dark blue sort of hue, instead of just pitch black like it currently is.