hi. how can I check my billing information on a iTunes store?

Could you tell us what kind of billing information is causing you trouble. Do not include any personal details, just an outline of the problem.

Hi

To check and update your Apple ID and iTunes Store billing information, follow the instructions here:

Change or remove your Apple ID payment information - Apple Support

To view your purchase history in the iTunes Store, follow the instructions here:

See your purchase history in the iTunes Store - Apple Support