how to use the untap symbol in magic the gathering

[SlowFast]

how do u use untap symbol

i know how to use tap symbol i just tap the creature but dont get untap like does the creature have to be tapped for me to use it also can i use it first turn also can i use it after i attack

[Arix]

It's exactly like the tap symbol, except opposite - you can only use it while the creature is tapped, and it untaps the creature.