nyctea scandiaca. Regularly getting food for a family or few dozen people would not be hard. To regularly feed 2,000 people using stone age technology and no seeds stores will not likely be possible unless they splinter off into smaller groups (and this certainly has risks of factionalism.)
First needs: Finding a safe, plentiful edible water supply. Then protecting it against human and animal pollution.
Secondary needs: Making simple hunting and defense weapons and building tools
Tertiary needs: Initial shelters. Natural canopies. Lean-tos. Ideally, caves.
Fourth: Foraging for edible plants and non-toxic grubs, various crawling and flying invertebrates and small mammals, mmmmaybe proto-fish and birds.
Fifth: Containers need to be developed as quickly as possible. With a population of 2,000 people there needs to be a mechanism for communal and individual food storage. Use nature’s found objects first: dried gourds, crustacean shells, large seed pods, edible, broad flat leaves, animal skins, inflated animal stomachs for leather pouches, tree hollows. Then after immediate needs are met, try expanding our technology using hollowed bones, wood containers, weaved straw baskets, leather stitching. Much later, when fire is mastered, ceramics, glassblowing and metalsmelting might be attempted.
Lastly: Heat. Warmth.
Do not be surprised if significant-to-huge numbers of the initial 2,000 colonists are injured or severely moralized, or killed outright at this point from bacterial or fungal poisonings, or simple plant toxicity, lack of food, illness from weather exposure and/or death by misadventure or accidents. I suspect at this stage plant life and animals might prove to be far more toxic than beneficial to modern-day humans. Even fresh water might have parasites that would make them deathly sick, and if THAT’S true, chances of survival are very grave. They might not even safely boil the water for safe consumption. With what fire? In what container?
Long term shelters: Unoccupied caves near fresh water supplies (ideal) or lean-tos near fresh water supplies. Keep in mind there may well already be predators there. They may be an ognoing source of food and possible domestication, or an ongoing dange.
Firemaking needs to be rediscovered and passed on to as many people as possible.
Next: hunting weapons, crude knives, sharpened sticks, stabbing spears with spearheads, stakes. For short range throwing weapons: rock slings, even rock-and-vine bolos I could see.
Next: building tools like hammers, sledgehammers, wood stakes, wood nails, stone stakes, quartz nails, vines for lashing things together. Shovels, pickaxes, axes. These would need to be made more durable than the hunting weapons, if possible, because these would likelier be for communal use.
Next: rediscovering technology: the so-called so-called “simple machines.” Some would be easy to make, like the inclined plane, the lever. Developing a reliable screw, or gear would be a major technological breakthrough, as would refining the wheel-and-axle or even a simple pulley.
Functional sling shots, bows and arrows capable of taking down game are deceptively complex, unless you’re skilled in making and using ancient technology.
It would be a fine thing if there were enough surplus wood, vines, nails, stone, and bone supplies to begin making simple furniture. Refinement of furniture making skills, along with shelters, would lead to other developments.
All of these things would take a generation or more to refine from basic concepts. To do this you’d need time to build up food stores and practice zero population growth, a working society is possible. Once that happens and population sizes are stable then move on to phase two: an educational based euthenic society.
10 -20 generations is entirely too soon. This might happen within two millenia.