Umrah has four parts. Knowing their order beforehand takes most of the worry out of the day itself.
Ihram
The state you enter before crossing the boundary, and the intention you make. Your group will tell you when the coach is approaching that point, so listen for it rather than watching the clock.
Tawaf
Seven circuits of the Kaaba, beginning and ending at the Black Stone. Keep to the outer rings if the crowd is heavy. A circuit walked calmly at the edge counts exactly as much as one fought for at the centre.
Sa’i
Seven lengths between Safa and Marwa. The distance is longer than it looks on a plan, so pace it. There is a marked lane for wheelchairs, and chairs can be hired at the entrance.
Halq or taqsir
Cutting the hair, which closes the Umrah. Barbers work in the streets around the mosque at every hour.
If you lose your group
Agree a meeting gate before you go in, not after. The mosque has many, they are numbered, and a number is far easier to find than a person.