Homonids are the ancestors of the humans, but much more human-looking than apes.
A homonin is the same, with a subtle difference of importance to scientists.
Homonins are bipedal apes.
That depends on your definition of prehistoric - most scholars consider prehistory to end with the first anthropogenic (man-made) record of a particular event. Some consider this to be 'The Epic of Gilgamesh' - a 2,100 year old Babylonian epic, widely considered to be the first evidence of literature. However, I will assume you mean the stone age, which is comprised of the paleolithic, mesolithic and neolithic (in that order.) 99% percent of this period is encompassed by the paleolithic, which charts eveything from the earliest tool use by homonins (a transitional group between apes and humans) around 2.6 million years ago to 10,000 years ago. Again, I will have to assume you mean the period around the last ice age, so the mesolithic and neolithic, and are inquiring specifically to the philosophy of Homo Sapiens, and not other species of humans. From what scant evidence we do have, we believe that all humans lived in hunter-gatherer communities, similar to those of the Native Americans, indigenous amazonian tribes, aborigines, inuit and masaii. Preserved relics suggest that females generally held an important status in society, with fertility being a particularly respected property. By looking at hunter-gatherer societies that have endured since prehistory, we can observe certain philosophies and ethics, such as a connectedness with nature, that were probably excercised around 10,000 years ago. If you want to obtain more specific information, I suggest you research cave paintings, and the beliefs of hunter gatherer societies around today.