Getting Started in Escape from Tarkov

Your PMC faction (USEC or BEAR) is currently a cosmetic choice only — pick whichever appeals to you, it won't affect gameplay.
Your Alpha Container holds a few items that survive even if you die in a raid — use it for meds, ammo, or rare small items you can't afford to lose.
You start with access to only 3 traders (Fence, Ragman, Therapist) — more unlock by completing main story quests and leveling your PMC.
Keys and keycards are valuable — some unlock entire areas or the Labs map, which holds some of the game's best loot.