How to use textures in material graph?

Hi! No coder here, is anyone knows how to use textures in material graph? It looks very familiar, I expected behavior like in blender or redshift, but can’t figure it out.

Textures has this blue “texture_return” out, non of the shaders I see have it. Color input not seemingly working too, it’s not texture color? There is sometimes “texture_2d” input, but I didn’t found node that produces this output. I see one inside the “file_texture” node, but I can’t copy it from there.

Is that even possible to drop PBR textures into a material graph, modify textures on the fly with brightness-contrast, curves, color correct, etc? It looks very possible, drag and drop working as expected, but for some reason, I can’t get it working:)