First night
Punch wood, make a pick, hide. Fighting a horde with a wooden sword is a restart.
Spawn shelter notes sit in additional guides.
Nether hub
Boat on ice in the overworld, or a safe tunnel in the Nether. Open lava lakes are not a hub.
Mark the portal with a unique block so you do not walk into someone else.
Redstone doors
A piston door beats a wooden flap if you play on a server with griefers. Keep a backup entrance.
Do not wire the only lever outside the wall.