Unfortunately, you can’t create an account on AWS without giving in credit details. But you may want to read this answer completely:
AWS has a free tier at its disposal. That lets you use most of its services for a year. There are certain limits on the usage of these services. As long as your usage stays in the specified limits, AWS will not charge you that means they are available to you for free.
If your concern is just learning AWS, then these limits should be more than enough. Now this is the reason why AWS wants you to give in your credit card details. Another important point is, that AWS will notify you if you are about to exceed these limits and it will also notify you when your yearly subscription ends. Unless you approve of it, you will not be charged.
So, you may go ahead and give in your credit card details if that suits you.
You can understand better from the AWS Course in Boston.