Training 

If you have never performed an exercise, try a couple of warm up sets to get into the movement and take it from there. Once you are comfortable with an exercise, the last 3 or so reps should be at a 10 on the difficulty scale. If you are performing a big over head lift, get someone to spot you if needed. This can be a friend, training partner or a fitness professional in the facility 

Its best to workout at whichever time is most convenient for you. The time when you feel you will get the most out of the session and when you will enjoy the workout. Depending on the type of workout, nearing bedtime isn't optimal but around 1.5 to 2 hours after eating is ideal.

It depends on a lot of factors, sometimes you will find you are sore, whereas other times you won't be. Usually soreness occurs when a muscle is stimulated differently but this is not always the case. A workout can be very challenging and result in no soreness and vice versa.

Entering your stats on Trainerize is vital so I can see the best way to progress you. Generally the best ways to progress are upping the weights and where we can't, changing rest time and tempo are the next best options.