Click on the little triangle drop-down button next to the word, "Normal".
Then drop what you're doing and go here, or you're going to get REALLY lost when working with AE:
There is no any triangle drop-down on my screen. Can't you see a red line instead?
Well, of course there's a triangle. Look below the red line. There's the word "Normal"
Now, why there's none for the layer above it is tough to tell. We don't know a thing about your software versions or your system:
The software isn't as straightforward to use as you might think. Certain OS/Hadware/Version issues arise.
I am talking about first layer. You talking about second.
And I also tell about it that my layer I set to 3D. Maybe that is a problem? But why? Why that MODES are not available in 3D?
if your first layer is 3-D and you have Ray-traced rendering turned on the blend modes are disabled.
All of these depends of ray-traced option?
You should have seen this warning when you enabled Ray-traced rendering:
If you need Ray Traced features and you need blend modes or any of the other NOT RENDERED features you need to pre-compose the RayTraced layers including a copy of any lights or cameras in the animation that must be in both comps, then change your main comp to a Classic 3D. You can tie position of lights and camera animations in the nested RayTraced comps using expressions so you can do camera moves. This is how that works.
If it were me I would be using another option for extruding elements like C4D Lite or I would work out the composite so that I didn't need blend modes. Simple as that.