Nodes: can't find material output or Diffuse BSDF I'm a new user of Blender and I wanted to try using bump maps.

I've watched a few tutorials online, looked here on Blender.SE and on the Blender guide, but I'm a bit stumped because I have different options than what I saw in the tutorials:

This is what the tutorial show.

I cannot find the material output or the Diffuse BSDF node anywhere. I'm wondering if I need to change my settings or if I am doing something wrong. I made sure to look at tutorials for the same version of Blender than what I use, in case it might be an issue.
Maybe you're not in Cycles Render mode (top horizontal menu bar), or maybe you are, but in the Node editor you are not in Shader mode (bottom horizontal menu bar)?