The key metrics to understand:
Lumens is the measure of total light output. A floor lamp intended to illuminate a room needs at least 800 lumens and ideally 1,200 to 2,000 lumens for a meaningful contribution to room lighting. Lamps below 400 lumens are ambient pieces they look good but they do not light the room.
Colour temperature affects how bright the light feels even at the same lumen output. Warm white (2700K to 3000K) feels softer. Cool white (4000K to 5000K) feels crisper and is better for working environments.
Beam angle determines how the light is distributed. A wide beam angle of 120 degrees or more distributes light across a broader area and is what you want for a floor lamp that genuinely lights the room.