This is earned by participating in 20 games of any type (win or lose). This achievement is accumulative and won't take long to obtain by playing the game normally.
If you want to speed up the process, load up an Exhibition game with these settings:
Arena/Map: Any
Team Size: 1v1
Bot Difficulty: No Bots
Mutator Settings: Max Goal = 1
Now you can pick any team you want (it will only be you) and simply make a goal which will end the match immediately and count towards a win. Rinse and repeat this method 20 times for your achievement.
Here's a visual reference as to how easy and fast it is to create and finish an Exhibition map for this achievement: