There is no way of telling for sure when labour will commence after your baby engages. Back 20years ago they said with a first baby it was 3weeks from the time the baby engages until its likely to be born however think this was more an old wives tail as women go into labour when bubs head is not engaged so its not an accurate meassure but certainly reassuring that its ready to go anytime.

As for getting comfortable I found the bath great for comfort during the day. Also bean bags are good if you have one. You can put your tummy in it and kneal and lean over it which might help and plenty of pillows in bed for between your legs.

Unfortunately at this late stage in pregnancy it can be very hard to get comfortable until after baby is born. I hope you don't have long to wait