Cannot change Color or Material

Alright. So I’m new here and I am encountering a problem that seems quite simple and I want to fix. It seems that I cannot change the material or color in blender, but instead getting this instead of the usual UI.

Hello! All you need to do is expand the section that says diffuse by clicking on the arrow next to it. That section is collapsed right now, and you just need to expand it to be able to change the color.