The shar‘i texts which indicate that the one who makes mistakes is excused, such as the verse in which Allah, may He be exalted, says (interpretation of the meaning): “Our Lord! Punish us not if we forget or fall into error” [al-Baqarah 2:286].
And Allah, may He be exalted, said [in a hadith qudsi]: “I have granted that”, as is narrated in Saheeh Muslim (126).
And Allah, may He be exalted, says (interpretation of the meaning): “And there is no sin on you if you make a mistake therein, except in regard to what your hearts deliberately intend. And Allah is Ever Oft-Forgiving, Most Merciful” [al-Ahzaab 33:5].
And the Prophet (blessings and peace of Allah be upon him) said: “Allah has forgiven my ummah their mistakes and forgetfulness, and what they are forced to do.” Classed as hasan by al-Albaani.
These texts indicate that whoever does something that is contrary to what he is obliged to do, because he forgot or out of ignorance, is to be pardoned. The one who is mistaken also includes the one who is ignorant, because the one who is mistaken is anyone who does something contrary to the truth without intending to.
Therefore, you do not need to repeat your wudu or salah according to the evidence above, but you should nevertheless make du'a and repentance and ask Allah to overlook your mistakes. Now that you know the correct method of doing masah, if you do it incorrectly again, you will have to repeat it, as you are not mistaken or ignorant now.
And Allah knows best