For brightness, try to buy your bulbs by Lumen output, which is the amount of light they give. Improvements in technology mean that Wattage figures constantly get out of date. There has long been a tendency for suppliers to recommend a slightly dimmer lamp as "equivalent" so they can exaggerate the electricity saving. LEDs have more light output per watt than older energy-saving lamps.
A medium room might need about 1200 lumen. A larger room might need about 1600 lumen. You may provide it with one central pendant or with two or more lamps. A bedside lamp may need around 350 lumen.
Globes, GLS and golfballs have a pearlescent glass cover that makes the light more diffuse and cuts glare.
Don't use spotlights if you want to illuminate a room. They are intended to illuminate a spot.
You can control room comfort with a combination of pendants, table and standard lamps.
Dimmers are tricky because technology keeps changing, and you need to buy lamps and dimmers that are compatible. Next time you need a replacement lamp, the tech may have changed. Many modern lamps are not dimmable. Lamps you bought a few years ago, or those on clearance, may be less efficient, and they also get dimmer with age.
For most household purposes "warm white" will be correct. You might want "daylight" if you are colour-matching for things that will be used outdoors. Major manufacturers like Osram and Phillips tend to be better at true colour.
Colour-changing lamps are God's way of telling you that you have too much money and are obsessed with gadgets.