2 things you should look into are:

*bevels - you should bevel edges, it makes them less sharp which is a good thing as edges are not really sharp/crisp anyway. if you look at the light on the edge of your desk you will see 3 tones not 2. the way you do this in 3D is with either the bevel tool or micro beveling -adding an edge loop really close to anther edge-

*UV mapping - this is super important! this is how the texture knows how to wrap around the model. you have streaking on your textures which is because you have not unwrapped your UVs. so they are stretching. I'm sure you could find a tutorial on how to do this, its fairly easy once you get the hang of it. this might also be the reason your bump map isn't working.