Uh. Even if you misuse the card, it's no MORE of an issue. Of course it is unwise to spend more than you afford. That goes without saying, and is irrespective of your credit score. It's actually advantageous to have a higher credit rating. It can make the difference between getting a home loan, or living in your parents basement.
Did you kids just get off the boat?
Your credit score is not a legal issue, or even an ethical matter, in reality. Worst case scenario, you get an AMEX card with unlimited balance. That is a good thing, guaranteeing auto loans, and larger lines of credit.
Take that card and only use it for purchases that you would otherwise use cash or debit, knowing for certain that you'll pay the balance on time, every time. This increases your rating, as a reliable and credit-worthy person. Yes, the temptation to spend more than you have is the ONLY caveat. Otherwise, your creditors are pleased with your reliability, offering lower rates, and improved lines of credit.
If this seems somehow underhanded or unlawful, it is not, and those answering the phones at your banks will readily admit that the better your credit score, the better! They just want to get familiar with you, and feel confident that you are responsible with your money.