Everyone says that before westerners came they had no concept of ownership so did they trade with each other? What if one tribe had a really bad year with food or something did they stockpile resources or anything so they could get food from other tribes?
I am not going to get into specifics of a hypothetical situation where a tribe is starving, but I do want to address your question about trade. The aboriginal cultures of Pre-Columbian North and South America were incredibly diverse and complex. I am going to assume you are mostly interested in North America. The trading networks of tribes here were mostly centred around the same things that early European settlers relied on: riverways. In particular, the Great Lakes and Mississippi River represent a large trading network that existed for generations pre-colonization. Relatively large settlements dotted the Mississippi and Great Lakes, the most famous of which was Cahokia. Cities like Cahokia relied on their strategic placement on the water way, and facilitated the trade between the North and South. This trade was obviously very lucrative for the Cahokians, although because this was a barter economy it is hard to measure what their exact wealth was. Regardless, the aboriginal societies were quite well developed, and these same trade networks would be mobilized when the Europeans arrived. For example, aboriginal tribes that never had contact with Europeans might receive European goods down the trade network.
When Europeans first started trading for furs for example, the tribes they were purchasing from weren't generally the ones doing the trapping, but were trading for those furs from sources farther down the trade network. Indeed, the Europeans simply began taking part of these existing trade networks. As to the idea that aboriginals had no concept of ownership, this mostly applies to land rather than personal possessions, and varies wildly. It's dangerous to generalize such a diverse group of people, but for example, the trade of Manhattan for "beads" as the popular story goes mischaracterizes what the natives there likely thought they were getting into. Owning distinct parcels of land is not a concept most east-coast aboriginals seemed to ascribe to, but rather we can think of it as shifting lines of control between competing tribes rather than demarcated property lines.
hi! regarding trade, you may be interested in this section of the FAQ
.. and you may be interested in some recent posts relating to this idea of people having had "no concept of ownership"