Hi, onurgonen, and welcome to the Community!
Having read that the Skype website can be confusing to find one's way around, here is an FAQ article that should provide the information you need:
Please note: To remove (delete) a Skype Account, you must contact Skype Customer Service directly. We here in the Community cannot process account-related service requests.
Online Safety Tips: Do not accept contact invitations from anyone whom you do not know, and change your passwords regularly and often.
Do you have a Skype trick up your sleeve? Share your Solutions and Tips with us!