Despite popular belief, you can still get a credit card if you have bad credit. Even with a score of 450, you can get a credit card from some banks or even a secured credit card. If you are in control of your spending this may be an option you should take.
A secured credit card is very similar to a regular credit card. The difference comes with the fact that you need to deposit the amount of money set as the credit card limit. The deposit acts as collateral in case you do not pay off your credit card. It offers banks a means of protection against customers with bad credit. All the purchases that you make with that credit card and all the reimbursements you make will help you improve your credit score. If you want to give up on the credit card, you can close the account and recover some or all of the collateral you deposited initially. You should check the terms of the contract to see how that is done.
The other option is to get a regular credit card. With a low bad score, options are a bit limited. There are still banks that will offer a credit card to a person with a bad credit score but the interest rates may be a bit higher. They may also add additional terms in their favor and the limit may be lower than what you would want. What you need to keep in mind is that when you have a bad credit score, the goal is to get it up. You may still want to get a credit card from a bank that offers them to people with bad credit but you need to be mindful of how you use it. If you can avoid making unnecessary purchases and pay off the credit card without any delays, you can get your bad score up, and then you can apply for a more advantageous credit card.