Find a cat in a village or swamp hut
Hold raw cod or raw salmon in your hand
Crouch or move slowly toward the cat
Stay still if the cat backs away
Keep the fish selected until the cat comes close
Use the fish on the cat until hearts appear
Repeat if the first attempt fails
Wait for the cat to become tamed
Equip a lead if needed to keep it nearby
Right-click the tamed cat to make it sit or stand