When humanity's ancestors left Africa, maybe 120,000 years ago, some turned left and ended up in Europe, while others turned right and ended up in Asia and some, eventually, in the Americas, crossing during the end of the Ice Age when the seas were lower and people could get across between what is now Siberia and Alaska. (In fact people left Africa in several waves, and many of course stayed, but let's keep it simple.) When the Vikings met the people they called Skraelings in the Canadian Maritimes around the year 1000, the circle was complete, and people whose ancestors hadn't seen each other for 120,000 years met again.
I've discussed the Vikings before, but here I want to focus on their visits to the New World. You can't really say they discovered America, because the natives knew it was there the whole time, and Columbus, not Leif Eriksson, was responsible for permanent contact between Europe and the Americas. But they definitely got there in their long ships.
The Vikings/Norsemen were a lively lot, with exploration, raids, trade, colonies, and permanent homes from Scandinavia to the British Isles to France (Normandy) to Sicily (where they established a kingdom) to Ukraine, Russia, and Byzantium. Everybody they met they called Skraelings, "the other," people who weren't them and therefore inferior.
Starting in the late ninth century they headed west from the Shetland and Hebrides islands, where they'd been well established, to see if there were any more good islands out there, and ended up in Iceland. This became a very successful settlement, where a language very close to Old Norse is still spoken today, and the glaciers are balanced by the hot springs heated by volcanos. The only big problem was that once they cut down the trees they didn't grow back, not having nearby trees to reseed them (as on the mainland). But the Icelanders were mostly sheep farmers anyway.
From Iceland they kept exploring west and got to Greenland in the late tenth century. The sagas tell that the explorers came back talking about how "green" everything was there in order to lure settlers, omitting to mention that most of Greenland is under a sheet of ice a mile thick (unfortunately now melting). Several Viking colonies were established, which lasted until the late Middle Ages, when the climate cooled and their sheep-farming (their principal occupation beyond fishing) just wasn't working.
In the meantime, explorers kept heading out, going north with the current up the coast of Greenland, where they hunted walruses, then west to Baffin Island, and south along the coast of what is now Labrador. Here they doubtless encountered Eskimo ancestors (who were heading east themselves and eventually reached Greenland, after the Vikings did, though their descendants survived when the Norse ones did not).
South of the Arctic Circle the Vikings got to L'Anse-aux-Meadows, on the northern tip of Newfoundland. This seemed like a much better place than what they'd been seeing recently. They called the region Vinland because wild grapes grew there. There were already people (ancestors of what are usually called Indians, or in Canada First Nations people) with whom they had an uneasy relationship. This is all described in the saga of Leif Eriksson, but for a long time it was considered fanciful. Then archaeologists started digging and found all sorts of Viking objects, as well as the remains of the sod long-houses they had built. L'Anse-aux-Meadows is now a "living history" site, with reenact ors and everything, as well as ongoing archaeology. You can visit it, and Newfoundland would love you to do so.
Vinland really was too far out, so although there was at least some Viking habitation there for twenty years or so, including women and families, they pulled back to Greenland. This has not kept Scandinavian-Americans in Minnesota from imagining that they somehow made it a couple thousand miles further overland to reach their homeland.