Types of yarn.

Yarn

There are two types of yarn in the world.
1)Natural Fiber Yarn  :ALPACA, ANGORA, CAMEL ,COTTON ,HEMP, LINEN, MOHAIR, SILK, WOOLEN  etc.
2)Synthetic Fiber Yarn:. ACRYLIC, NYLON, RAYON, POLYESTER, BAMBOO etc.

But among of these types of yarn ACRYLIC, WOOLEN or COTTON is the best option for beginners.

Because these types of yarns are generally quite uniform in thickness. So that if you make a mistake you can easily undo it.
Basically Sweaters, hats, gloves are making with woolen; Coller / Neck, bags are making with cotton or acrylic yarn. But amigurumis are made  almost all kinds or yarns.