This is pretty good for a beginner, (and seeing that I am also a beginner) I don't have alot to tell you, but here's something:
-The whole thing seems very seperate. Try blending each layer together by using gradients, matching colours, and using overlay layers.
-Make the colours more dynamic! Add light focal points (face, etc.) and dark points, such as around the edges.
-Try adding more to the 'under/around the render' section (blood splatter is this case). Add in a few different types of splatters. Using layer effects like colour burn or lumonosity also give a varied look!
-Your text placment is not bad, but again, the colour choice could be better in order to round in the colour theme.
-The backround seems kinda out of place, maybe a grey-to-light blue gradient (on low opacity) would look better, and not stick out as much!
Hope these tips helped!