Hi There !!
Its nothing to get worried about .. Just be yourself while instructing , be encouraging towards them..
Now coming to theraputic part of it :-
1) See when is the patient being mobilised from the day of operation ?
2)IS the Patient with the drains ??
3) Do not adduct the operated hip while bringing the patient from lying to sitting position or while sitting to standing or vice versa ..
4) Check for sensation in the operated leg , as the patient may buckle post operatively due to spinal anasthesia (fentanil )..
Be bold and handle the case with positive attitude ,that itself will help when you work with presence of mind
All the best ,
Radhika