Assigned as General Manager to a hotel suffering from bad revenue and bad reputation in services. What would be your first decisions ?

You can't take any decision wihtout knowing the root cause of the problem. If you have a pain in your knee, the doctor just doesnot chop your foot off. Same approach must go in. The assigned GM, must place all department Managers on their toes, from sales & marketing, to room service, finance and front desk in ensuring everyone is giving their 110% to the hotel. Then onwards, he/she can analyze previous stats, see the body language of each staff and see who should stay and who should not. But in short, find the root cause, and start the healing process ASAP.