If you've gotten rejected on all of them, that means that you applied for all of them, which means you cannot get any credit card for a year. When you apply for a credit card, they check your history of how much you have been applying. If you have applied for too many of them in the previous year, then you will be rejected. You cannot get a credit card until you stop applying so much.
Also, by law, you cannot get a credit card without a cosigner, a job, or proof of income, until you are 21. If you don't have any of those 3 things and you apply when you are under 21, then they must reject you.
What you should do is to stop applying.
You should not apply again until (1) it is over a year since the last time you applied, and (2) you are 21, have a job, have proof of income, or have a cosigner.
When you do apply, you should apply for ONLY ONE and then stop, immediately. If you apply again for all of them, then you will be rejected on all of them again.