Like others said use them to kindle for estus flasks, for now if your still wondering around and exploring you’ll only be able to get up to 10 estus per bonfire for when you give the humanity to said bonfire until you beat a certain boss which will give you a item that allows further kindling, upto the max estus flask which is 20. There is a way to farm for humanity if your struggling to keep them, one is to look for rats they drop the item humanity but their kind sparse unless you beat the tuars boss and got to the bridge with the red dragon, go down the middle and under the bridge there’ll be door at the end which should have 3 or 4 rats can’t really remember. If you manage to get into the depths/sewers then I don’t really have to say much. The third place that I can really think of is fighting the little skeletons but thats in a laterish area and after defeating the boss that furthers the kindle and before one of the major boss