I think it would be better if in the title it said "Cuenta lo más alto posible - Un Minuto Sprint" and for "ir" to be "Fuera" Nice that your translating some of these quizzes
Ir is go in it's infinitive form, in this case you are trying to say 'go' as in 'Ready, set, go' which would 'En sus marcas, listo, fuera'. Fuera can mean go or out as in 'Fuera de mi vista' (Out of my sight). But in this case, fuera would make more sense. I tried explaining it as best as I could, so I hope this helped a bit ;)