I have not performed a valid prayer, so should I repeat these prayers?

The questioner should clarify the type of errors he believes invalidated his prayer. If the conditions for the validity of prayer are not met, then it is considered invalid and must be made up, whether the worshiper was ignorant or not. This is the view of the majority of scholars. However, Sheikh al-Islam Ibn Taymiyyah held the view that whoever misses a condition or pillar out of ignorance is not obligated to make it up. Nevertheless, making it up is more cautious and better for one's conscience.