how do sell my iTunes card who I accidentally buy the in online

Hi lutz224

welcome to the Apple (user-to-user) Community.

Re: I accidentally buy lots of iTunes and how can I sell it and give my money ?

Seems Apple / iTunes / Gift Cards cannot be exchanged for money.

Gift cards can likely be redeemed and used in an Apple ID Account for purchases from Apple:

What you can buy with your Apple Gift Card or Apple Account balance - Apple Support

See if Gift Cards can be used as a payment method in your country or region:

Payment methods that you can use with your Apple ID - Apple Support

How to redeem your Apple Gift Card or App Store & iTunes gift card - Apple Support

What to do: If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card - Apple Support

All the best :-)