Firstly: What to Say When Entering Al-Masjid Al-Haram
It is sunnah to supplicate upon entering al-Masjid al-Haram, like other mosques. One says: “I seek refuge in Allah the Greatest, in His Noble Countenance, and in His Pre-Eternal Sovereignty from the accursed devil. O Allah! Open the doors of Your mercy for me!” Upon leaving, one says: “O Allah! I ask You of Your bounty.”
Secondly: Entering with the Right Foot
It is sunnah to enter al-Masjid al-Haram with the right foot, like other mosques.