Which is better to learn molding, forging, casting, mold rolling?

There are four directions to learn molding, forging, casting, mold rolling, which direction is better?

Forged devices are better. Forging can eliminate defects such as loose as-cast metal during the smelting process and optimize the microstructure. At the same time, due to the preservation of complete metal flow lines, the mechanical properties of forgings are generally better than castings of the same material. For the important parts of related machinery with high load and severe working conditions, forgings are mostly used except for simpler shapes that can be rolled, profiles or welded parts.
Casting is a method of pouring liquid metal into a casting cavity suitable for the shape of the part, and after it has cooled and solidified, the part or blank is obtained.