What do you need to make soaps? How to make it?

A simple way to answer these questions is you'll need fatty acids (liquid, solid or powder) and caustic soda (Sodium hydroxide or potassium hydroxide). The process of making soaps (saponification)  is a chemical reaction between the acid (fatty acid in oils) and the base - caustic soda. The end product is a compound of metallic salt of fatty acids which is soap