What Ihram is, where you must enter it, what it permits and forbids, and the Talbiyah every pilgrim recites.
Ihram is the sacred, consecrated state a pilgrim enters before performing Hajj or Umrah, marked outwardly by simple unstitched white cloths (for men) or plain modest clothing (for women), and inwardly by the intention (niyyah) to perform the pilgrimage solely for the sake of Allah. Once in Ihram, a set of restrictions apply until the rites are completed.
A meeqat is a fixed boundary point around Makkah. Anyone travelling to Makkah for Hajj or Umrah who passes through or over one of these points must already be in the state of Ihram.
Recited repeatedly from the moment of entering Ihram until the start of Tawaf (for Umrah) or the stoning of Jamarat al-Aqabah on the 10th of Dhu al-Hijjah (for Hajj).
Use the Talbiyah Counter to keep a running tally of how many times you recite it.
Details such as exact meeqat coordinates for connecting flights, and the fiqh of accidental violations (which may require Fidyah/Dam), can vary — always confirm your specific route and situation with a qualified local scholar or your Hajj/Umrah group leader.