First suggested trail to visit Petra: from visitor center -Basin area (Restaurant area) starts with the Siq , the Treasury, Street of facade, Theater, Royal Tombs, Great Temple Complex and princess palace, can be taken in first day - 4 hrs and it will cost you 50 JD, later on you can walk all the way to Monastery in the same day- 2 hrs and it can be self guided (with guide will cost you another 50 JD).
Way 2 in the second day- from visitor center to High Area of Sacrifice and Back Area (Wadi Farasa) and the guide will cost you 50 JD (Guide is Highly Recommended) , you may continue to Mount Aroun in that day (Guide is recommended and will cost you 50 JD)
During my hundreds of visits to Petra, I was able to cover the main trail, the Monastery and the back trail - Wadi Farasa and high area of Sacrifice few times, this involves walking of around 16km, and climbing over 2000 steps, equivalent to going 213 floors according to my iphone health application.