Greetings @Cinthia !
Libraries have been one of my passions since childhood. It has been very refreshing to find that you are creating one in UE5! The Dark Crystal is also one of my favorite films, as I am a Jim Henson fan.
As @PresumptivePanda pointed out, your reference photos are both powerful and beautiful!
The spiral stairs you have built are like a strand of DNA - the pathway with which information exists from one level to the next. The texture you’ve chosen for the walls and banisters are both rich and fitting.
Are you modelling your own assets and using your own textures? Which lighting from your reference photos are you aspiring to achieve (amber, cool, bright, naturally lit, dimly lit)?