Help with texturing

Hello, Blender artists!

I recently started learning Blender, following some tutorials. Few days ago I started my first personal (non tutorialized) project. It is a robotized pharmacy warehouse that I’m doing to give a better idea of what all those blueprints and explanations from my project should look like. While the model is mostly finished, I have a lot of trouble with the textures and illumination (I will work on that later once I have the correct texturing).

Here you can see how it currently looks rendered with the current settings and the .blend file just in case anyone wants to check it out a bit more.

My ideas:

  • All that gray structure should look like steel, or painted steel, but right now it looks nothing like steel, even that I tried following some tutorials.

  • The door is white right now, it is not necessary for it to be white, so if anyone has a better idea, I would like to hear it, but it is also metallic, it can be painted too.

  • That protuberance in the door is a simplified version of keyboard+monitor.

  • The black thing left of the door is a conveyor, it may be improved, but right now is the best looking of all of them in my opinion.

  • The hole over it is just that, a hole where items are placed by the robot.

  • The door has a window, it looks decent in my opinion

  • All those horizontal lines are shelves, I still don’t know exactly what material will they be made of, but something slippery, I’d like to make a texture that shows that it is slippery.

Any help will be appreciated