If the ball lands on the number you’ve wished for, you win. Every time the croupier rotates the wheel, players have an opportunity to bet their money on one of 37/38 numbers (depending on the Roulette type).
There are several betting systems and instructions, but your luck determines the result. Throughout the years, it remains one of the easiest gambling forms to master, it also depends on luck more than slot machines and other games.
Pick a number, any number! In fact, that’s the point of the game of Roulette.