Kindly refer to the following link(s):

Is it sunnah to fast the first 9 days of dhul hajjah?

Whats ruling on Fasting on 10 days of Dhul Hijjah

Deeds to be observed during the first 10 days of  Dhu’l-Hijjah (which is better days of dhul hijja or nights of Ramadan?)

Do deeds get doubled in the 4 Sacred Months: Muharram, Rajab, Dhul Qidah, Dhul Hijjah?

He habitually fasts the white days, shall he fast the same in dhul hijja?

The takbeer after Fard prayers begins on the fajr of Arafat and extends till the Asr of 13th