How to score in darts really depends on the games you’re playing. Different darts like the typical ‘01 darts, around the world, baseball, and cricket have specific rules and scoring systems.
Let’s get down to the very basics – understanding different sections of the board. The surface is divided into 20 similar segments/sections. Each segment has a number above it. There is a total of 20 numbers, from 1 to 20, representing the 20 segments.
To score, you’ll need to throw darts at the board. Different areas will reward you with different scored points. Only the darts which stick on the board surface until the players collect them count as scores. If a dart hits and then falls out before the player collects it, it doesn’t count. If a dart hits the wires and bounces out, it also doesn’t count.
Source for detailed information: https://dartsgamecenter.com/how-to-score-in-darts