As you jump from star system to star system in Starfield, you'll find hundreds of new settlements where you'll need to practice the etiquette of holstering your weapon. Having a weapon unsheathed in a civil settlement causes unnecessary alarm among the NPCs.
Starfield: How To Holster Weapon
In Starfield, remember to holster your weapon in settlements to avoid alarm and tension. It also boosts your movement speed. Learn how in this guide.