How can one dispose of a paper on which there is sorcery and strange names, and which was given for the purpose of attracting a groom, knowing that this act is considered polytheism (shirk)?

You did well by refraining from using the hijab (definition) that seemed to you to contain sorcery or magic, for such a thing brings no good, and if it contains magic or sorcery, it brings nothing but evil. Your abstention from it will be a cause for facilitating your affairs and rectifying your situation. We do not specialize in the method of nullifying such things, and we advise you to consult one of the trustworthy Islamic exorcists (ruqat shar'iyyin).