On the Races Meaning?

(idiomatic) In or into a process of energetic engagement in some activity; in or into a phase of conspicuously increasing satisfaction or success.

What does it mean to be at the races?

informal. usually with negative Competing with a chance of success. 'they were never quite at the races against Rangers'

How do you use off to the races in a sentence?

an expression characterizing the activity or excitement that is just beginning; [we are] leaving for something interesting or exciting. The tour bus is out in front waiting and we've said goodbye to everyone. Looks like we're off to the races.