How to boost the trophy "What do you want, a medal?"?

[WhiterWhite00]

I'm asking because when me and my friend complete the first of the five league races, it says:

-"23 hours remaining" if I put "scheduled" in league settings;

Or

-"race starts in 30 minutes" if I don't set "scheduled" in settings, but why do we have to wait 30 minutes?

What settings do I have to set to play 5 normal races one after the other, like a championship in offline mode? Thanks