There are actually two accounts of this interaction that I know of and they are brief. They are the saga of the Greenlanders and Eirik the Red's saga, known jointly as The Vinland Sagas. They cover the same events, but sometimes collaborate and sometimes contradict.

The Vikings certainly did encounter Native Americans, providing descriptions of the new world and its inhabitants in specific detail. While the sagas are very interested in the presence of wood (maple), fish, wheat, and "grapes", they are not especially interested in describing the natives. The best we get is from Eirik the Red's saga:

They were short in height with threatening features and tangled hair. Their eyes were large and their cheeks broad.

It is also mentioned that they slept under "hide-covered boats".

At first, the Vikings traded with the Natives (Skraelings), exchanging milk or red cloth for pelts, although the Natives would have preferred the Vikings' weapons. The Natives apparently really liked both milk and the cloth, and traded pelts at whatever exchange rate the Vikings set. Later, the Natives return and attack (for reasons unstated) but are resisted and retreat. Nothing besides small skirmishes are reported. The weaponry is not explicitly stated, but it seems to have been arrows (the Natives were apparently unfamiliar with the axe).

Afterwards, they discover some Natives sleeping in "skin sacks" by the shore and kill them. In this way, the Vikings display a very casual approach to the killing of Natives, considering their loss of life to be of little consequence.

The sagas do not directly mention the L'anse aux Meadows discovered in the 1960's in Newfoundland, although that site is close to where Leif made his camp. (see u/sagathain's comment below) Other events are thought to have occurred in Nova Scotia.

That said, the Sagas are thought to be written in the 12th century, but our manuscripts are only from the 15th. So, at best, these are oral stories passed down at least 200 years before they were written down. This explains the discrepancies between them, but not how reliable they are. In broad terms, they are reliable (especially since L'anse aux Meadows was discovered), giving accurate descriptions of the coastline from the St. Lawrence river to New York City, and details of flora and fauna. In specific details, they are much less reliable, containing indiscreet plugs for Christianity interspersed with superstition and witchcraft.

Aside from the Sagas, we really have no other contemporary literary source of the subject, and they really only deal with the initial encounter of North America. So we just have to take them with a grain of salt. It is rather certain the Vikings did meet Native Americans, and likely they exchanged both goods and lives. The Sagas are the only record we have of their exchange, and they have very little detail on the subject.

For more information on what happened after the Sagas, u/sagathain has an excellent answer here.

While u/InactivePomegranate (this comment was removed, but the one by u/PalmamQuiMeruitFerat covers the same evidence) does a good job compiling the saga evidence, i.e. the only written sources we have on the subject, you may want to check out this answer I did a month or so ago on a related subject.

The short version of it is "while there is a long history of interaction between Norse peoples and Dorset/Thule people in Greenland, there is a lot of literary interpolation in the two sagas that throw doubt on the reliability of the account of events in Vinland."

Since writing that answer, I've seen arguments indicating that the site at L'anse Aux Meadows was utilized for far, far longer than is currently accepted, potentially as long as 150 years, but I haven't been able to track down academic sources on that, as opposed to pop-science ones, so I'm skeptical. That would be a massive change in our understanding and what types of interactions were possible, though, including the motivations for Bishop Eirikr's expedition to Vinland in the 1120s that results in his disappearance.