It's sometimes normal to gasp for air if you've been exercising hard such as running and then you have to stop and catch your breath.
However you should not normally have to gasp for air to breathe.
If you suddenly have to gasp for air to breathe then you should seek medical attention especially if you are continuously having trouble breathing.
When breathing you should not have to gasp for air if your lungs are working properly and you should be able to breathe in and breathe out without even thinking about it.
When you're breathing normally you breathe in air and exhale hair thousands of times per day without even thinking about it.
You shouldn't have to struggle to breathe and if you do constantly have to struggle to breathe then something is not right.