This is a pretty broad question. Not a ton is known about exactly how native populations lived, as there is nothing written down, but a good deal can be gleamed from remains and the records of Europeans.

A book on the topic I highly recommend is Changes in the Land: Indians, Colonists, and the Ecology of New England by William Cronon and John Demos. It gives an absolutely fascinating account of what we can tell about the area of New England before, during, and after the early Colonial period. Quick tidbits that I most enjoyed learning about:

-There were a lot more natives and native villages than many popular tales recount. The sheer number of natives that perished from disease before the English ever showed up is staggering.

-One of the reasons New England had such open under-growth was due to natives constantly burning down the low growing plants under the trees. This was done to make hunting easier, and had a massive impact on the ecology. The landscape changed drastically when Europeans drove them off and this practice stopped.

-The absolutely mind blowing amount of wildlife that America boasted before European settlement. Writers discussed flocks of passenger pigeons that flew overhead for entire days without end, fish and whales so plentiful they were thought to be infinite. So many deer that it was thought that a man would need not ever pick up a plow again - he could live off the land with ease!

(Obviously some of those claims are a bit exaggerated, as these are written by men with a vested interest in getting more support for colonization.) Nevertheless, the authors (and their research is very thorough) argue that what we see today in the wilderness is some miniscule percentage of what once roamed north America.