Well, the first piece of advice is to make it a tile-able texture… or you could unwrap the UV map in your 3d modelling program of choice and create a UV Map for it. It would be easier to show you than for me to explain it, however I am currently typing on borrowed time (laptop/hotspot) rather than my desktop due to power issues in the neighborhood.
In the second image… is there a side to the brick L-shaped wall? Or that could be a texturing issue, I am not sure which :\
As another poster said, you will definitely want to add molding to where the walls meet the floor and ceiling so they don’t appear to clip through.
Check out the displacement/tessellation tutorial here: 1.12 - Tessellation Multiplier | Unreal Engine Documentation