get cracking/rolling

get rolling

To leave or depart. Let's get rolling. We need to be at the airport by 7:30. There's nothing happening here—let's get rolling.
See also: get, roll
Farlex Dictionary of Idioms.

get rolling

Fig. to get started. Come on. It's time to leave. Let's get rolling! Bill, it's 6:30. Time to get up and get rolling!
See also: get, roll
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

get cracking/rolling

Begin, get busy, hurry up. The first of these colloquialisms originated in Great Britain in the 1930s and appears to have crossed the Atlantic during World War II. It uses crack in the sense of “move fast,” a usage dating from the late nineteenth century, and is often put as an imperative, as in “Now get cracking before it starts to rain.” The synonymous get rolling, dating from the first half of the 1900s, alludes to setting wheels in motion. It, too, may be used as an imperative, but is more often heard in such locutions as “Jake said it’s time to get rolling on the contracts.”
See also: cracking, get, roll
The Dictionary of Clichés by Christine Ammer
See also:
  • let's roll
  • leave it at that
  • let's get out of here
  • let's rock and roll
  • Let's rock and roll!
  • let's see
  • let's go
  • finishing touch
  • the finishing touch
  • let's get the/this show on the road