Is the Sa'i of Hajj on the Day of Tarwiyah valid without the Tawaf al-Qudum, knowing that there was impurity on the ihram garment during the Tawaf while caring for an elderly father, and knowing that I performed Hajj Ifrad and completed the rituals of Hajj, then got married and performed Umrah thereafter?

Scholars have differed regarding the validity of performing Sa'i before Tawaf. Ibn 'Uthaymeen favored the validity of performing Sa'i before Tawaf, citing the hadith: "There is no harm." Ibn Baz stated that the Sunnah is for Tawaf to be performed first, then Sa'i thereafter. However, if one performs Sa'i before Tawaf out of ignorance, there is no harm, and he cited the hadith: "There is no harm." This indicates that if one performs Sa'i first, it is sufficient. Therefore, your Sa'i is valid and sufficient, Allah willing, and there is nothing upon you. As for Tawaf al-Qudum, it is Sunnah for the Mufrid (performing Hajj only) and the Qarin (combining Hajj and 'Umrah) according to the more preponderant opinion of scholars, so nothing is required for its omission.