are always human. In addition, you dont hollow in the course of the game unless you speak to Yoel of Lordor. He will let you level up 5x for free. In exchange you will be marked with a dark sigil. After this has happen whenever you die from this point on, you will hollow. In order to prevent further hollowing, you need to give the firekeeper souls to the firekeeper. She will remove the dark sigil for x souls. In order to remove the current hollowing, you need a purging stone.
This game humanity is embers. You need to use a ember to be summon, summon others, etc. when you do use a ember, it gives you 30% on top of your current hp.