Before breathing, the first thing we need is lungs and nose, without lungs we would not live in this world

If there are both then the next step is breathing
step 1 : you have to calm down and don't be panic
step 2 : inhale the air using your nose
step 3 : If you have inhaled it then exhale the air you are alive with
step 4 : If you are used to it, try taking a deep breath and exhaling slowly
(If you have difficulty breathing, just use step 4)

WARING : If you are having a panic attack and you are breathing fast, I suggest you need calm down and follow the step 4

TIP : try to breathe outside air and inhale the inhaler too