Historians aren't sure about the identity of the "Skrælings" of Viking sagas, but the most likely candidates are the Dorset, Thule, Beothuk and Innus. The discovery of butternuts on the archaeological site of Anse-aux-Meadows could be proof that Vikings also went South, as Juglans Cinera doesn't grow in Newfoundland nowadays. It is unlikely it ever grew in that region, even in the warmer climate of that time period, as J. Cinera is sensible to storms and heavy winds. This means they could have met with Coastal populations in modern day New Brunswick or Nova Scotia, or even the modern day United States. This could also mean they got the butternuts through trading with Indigenous populations.

The Dorset didn't hunt large land mammals like the Thule (proto-Inuit), and their diet was constituted mostly of sea mammals like seal or walrus. At the time the Viking arrived in Newfoundland, the Atlantic walrus population (now extinct) was thriving. There is a bit of doubt as of wether the Dorset and the Viking could have met, as they were already competing with the Thule people at that time. The Dorset didn't use technology such as bows and arrows, dogsled and kayak. The Sagas mention injuries by arrows in skirmishes with the Skrælings, but you have to keep in mind that these accounts were written centuries after the fact.

The Thule (modern day Inuit) are a circumpolar culture. They developed advanced technologies that allowed them to hunt for larger sea mammals such as whales and they also were good at hunting caribou inland. They would live in Igloos on the seashore during Winter, hunting sea mammals and fishing, and they would move inland during Summer time to pursue caribou herds. They also have a complex Pantheon and a sophisticated iconography of soapstone and bone sculptures.

The Innus are an algonquian speaking people of the Northeast which share cultural ties with other modern day peoples such as the Naskapis, Atikamekw and Cree. They were mostly fishermen and berry pickers in the Summer and Caribou hunters in the Winter. They would use nets at the entrance of the huge rivers of Northern Quebec to catch salmon, on which they could probably have fed their community for months.

They would dry the fishes for later consumption. They would also fish for capelin when it rolled on the shore, clams, herring and so on. The berries they could pick were blueberries, raspberries, cloudberries... They would heat the berries to make a paste that they kept in birch bark. They didn't use pottery a lot, unless acquiring it from Southern peoples such as the Saint Lawrence Iroquoians which were sophisticated pottery makers living near modern day Quebec city and Montreal.

They would spent Summer months near the Innus on their fishing/seal hunting/beluga hunting grounds. Most of their cookware was made with bark, and they used hot stones to heat the stew they would make. The Innus had spiritual practices that have been integrated by other North American peoples in Modern Times into what is now considered Indigenous Spirituality, among these practices where the makushan, a feast where you would eat everything, the sauna or hot tent, and the shaking tent where you would invoke the land animals or sea spirits before a hunt. There was a great deal of spiritual connexion with the animals, especially the caribou, in their practice.

One man was responsible for caribou hunting parties, that involved prior purification, communication with the land spirits and outmost respect for any remnants of the animal (they never gave bones to the dogs). The dogs was the only domestic animal they had, they would be used for preventing intrusion on their sites or sometimes for hunting, but also as food.

Gender roles were split between men and women, women would be responsible for berry picking, picking medicine, cooking, skinning and preparing meat, getting wood, making needles and nets, and these roles were fixed. A man seen getting wood would be derided, for example, as it was a woman's work. Men were hunters, sometimes warmongers and fishermen. They could be gone for long periods of times.

Homosexual marriage was accepted, although one person had to take the role of the other gender in such an arrangement. What we call trans identity today was also accepted as "two spirit" and trans people often took the role of spiritual leaders. It wasn't a free-for-all neoliberal identity buffet, though, these gender roles were quite strict, and not abiding most likely meant to exclusion.

Sociality was organized around the family unit, unlike in agricultural societies, and although "divorce" was possible, they would be mostly monogamous. As for social hierarchy, there would be Seasonal authority, meaning when the bands were organized in larger fishing and trading posts during the Summer, they would elect chiefs that would carry the demands of the group to other groups during negotiations or settle quarrels, this involved very long tractations, and the first Europeans meeting them were puzzled by how long it was for them to take decisions and how long their speeches were.

On the opposite, war or hunting parties were mostly organized around one experienced leader whose authority was final. As of war, it was a seasonal activity, mostly carried between the salmon fishing season and before the caribou hunting season (you wouldn't want to travel Northeastern forests in June anyway, the blackflies would eat you alive).

War parties were constituted of a few young men - maybe around ten - and the actions taken would be mostly symbolical, rarely involving massacres. It was rare, and oral tradition and historical records mention a few occurence, with the Mi'kmaq, with the Iroquois, it might have happened with the Inuits at times. The Innus weren't really warmongers.

They would also travel for fun, and have plenty of time for games, discussions, music, dances and so on. There is no indication that their life conditions were especially harsh.

They had an economy called gift economy by anthropologists, meaning the more generous you were, the more respect you got, these there was no 1:1 ratio with trade, trading 2:1 meant you gained respect, trading at 1:2 meant you had to pay respect. In that sense, it was considered horribly selfish to keep food or things for yourself, and could have been a casus belli. Meeting with Europeans trying to trade goods 1:1 was probably a shock as they wouldn't have understood why they just didn't give away their nice stuff to them, a gift they would have paid in respect. They weren't culturally blind, though, and they understood the differences pretty quickly and tried to take advantage of them.

The most coveted Viking goods would have been luxury stuff such as metal tools (that they didn't quite use for their intended purpose, preferring stoneware and barkware, and using them as ornaments) and mostly flour. Flour (corn flour, let it say) was a very popular item they traded with Southern people.

I'm sorry I took so long with the Innu, I have to go teach. We don't know a lot more about the Beothuks as they were unfortunately the victims of a genocide by the settlers of Newfoundland, and there aren't any of them left. We know they used the same system of Summer posts/Winter posts as the Innu, though mostly with moose hunting in the Winter, and that they developed a culture that was really hostile to European invasion. They would also paint their bodies in red ocre for war parties.