Perform the task specified in order to unlock that poster. You can then see the things you already have by using My Cup's Rewards Option.

Effect - Code
Fifa World Cup Poster 1 - Win the World Cup once
Fifa World Cup Poster 10 - Qualify and win the World Cup with one team from each area
Fifa World Cup Poster 11 - Complete all Skill Challenges
Fifa World Cup Poster 12 - Complete the Global Challenge
Fifa World Cup Poster 2 - Win the World Cup twice
Fifa World Cup Poster 3 - Win the World Cup three times
Fifa World Cup Poster 4 - Complete the qualifying round with a team from Oceania
Fifa World Cup Poster 5 - Complete the qualifying round with a team from Asia
Fifa World Cup Poster 6 - Complete the qualifying round with a team from Europe
Fifa World Cup Poster 7 - Complete the qualifying round with a team from Africa
Fifa World Cup Poster 8 - Complete the qualifying round with a team from North America
Fifa World Cup Poster 9 - Complete the qualifying round with a team from South America