The Prophet (peace and blessings be upon him) said, “Islam is built upon five pillars: testifying that there is no true god except Allah and that Muhammad is the Messenger of Allah, performing Prayer, paying the Zakah, making the pilgrimage to the Sacred House (Hajj), and fasting the month of Ramadan.” (Reported by Al-Bukhari) Also, we’d would like to commend your pursuit of Islamic counselling.
After performing Tawaf Al-Wada` a pilgrim can offer salah as well as acts that do not take much time. So, performing salah or any other necessities that do not take much time do not affect the validity of your tawaf. May Allah reward all the pilgrim’s Hajj!
Allah Almighty knows best.