Your first week has one job: survive night seven. Every choice about where you settle and what you craft should serve that night, because the horde arrives whether you are ready or not.
Day one
Spawn, gather plant fibre and stone immediately, and craft a stone axe and a bow before anything else.
Pick a settlement near a trader. Traders give quests, and quests give loot faster than scavenging does.
Days two to five
Clear one small building per day through trader quests, and spend the rest crafting. Storage, a campfire and a workbench come first.
Start a base early, even a rough one. Digging out an existing building is faster than building from scratch.
Days six and seven
Spend day six on defence, not looting. Repair blocks, stock ammunition, and clear sightlines around the base.
On horde night, fight from cover with a fallback route. Standing on open ground is how most first weeks end.