If you have a credit score of at least 600 or above then you should be able to get a Walmart Credit Card or even a Capital One Credit Card.
When I had a 600 credit score I was able to get approved for A Capital One Credit card and also a Walmart Credit Card.
If you have a lower credit score than 600 you might have to go with a secured credit card through Capital One or another credit card company.
A secured credit card is a credit card where you put some money up as a deposit to secure the credit card and then you use that secured credit card like any other credit card and pay the credit card bills on time.
The deposit you put up to secure the credit card is your credit limit and the secured credit card will help to build or improve your credit score overtime as long as you use the credit card responsibly and pay the credit card payments on time.
Then you can get approved for other credit cards once you build up your credit score.