The signs on the map to guide you to perform side quests/ easter eggs (after you complete all main quests first)
As I have mentioned in the previous comment:
Talk about the second mission, when you get a motorbike running through the city. You have to wait 10 minutes for the contest to start. During that time you do what you like, earn money from matches or simply go sightseeing.
The story is still in development, each time the player chooses the appropriate answer, it changes the plot and difficulty of the game.
Thank you for giving me a little more idea to do it better.