hello, I would like to make a part for my horror game where blood would be dripping from everywere and slowly covering the walls, how can I do that(keep in mind that I have very little knowledge of unreal engine 4 which i am using)
Learn Niagra and decals. With these you can achieve what you want
Create a actor blueprint called maybe “BloodDroplet” add a little sphere mesh component with a red material.
Check simulate physics. Block the collisions you want it to hit. On the OnComponentBeginOverlap fire a line trace on the z axis downward and spawn a decal at location. Then destroy actor.
Spawn actor from class “BloodDroplet” anywhere you want and it’ll fall toward the ground, make a decal and the mesh will disappear leaving the decal.
That was very vague and there’s a bit more involved, but I would go about it like that. 
Niagara and decals are best solution for it.