Initially I'd stick to some kind of Basic regime.
So you work all the muscle groups every session then have 3 sessions a week, alternate days.
When you hit the muscles, only use 1 exercise per muscle group, 2 times each, going for around 8-10 repetitions of the exercise.
I would advise that most of what you use for now be machines, because free weights can sometimes require more than a basic technique and sometimes unusual stances and without anyone to show you, you might run into problems. Some Free weights could be done however, those that utilise a basic tehcnique, not more than one component to the movement, plus a simple stance, I.E. standing upright or sitting down for example.
So you're looking at something akin to this.
2 sets Leg extensions, 8-10 reps.
2 sets Hamstring Curls, 8-10 reps.
2 sets Back extensions, 8-10 reps.
2 sets Pec Deck, 8-10 reps.
2 sets Reverse Pec Flyes if possible, 8-10 reps
2 sets E-Z Bar Curls, 8-10 reps
2 set Tricep Pressdowns, 8-10 reps.
2 sets Machine Shoulder Presses 8-10 reps.
All of those with a minute rest in between.
Planks for Stomach. On the tips of the toes, resting on the Forearms, straight back, 30 seconds.
Keep all the weight light and in terms of the Machines, don't exceed 3 plates initially.
With Planks, add another 5 seconds a week.
With the E-Z Curls, add a tiny amount every 2 weeks.
With the Machines, if they have little 5lb things you unhook and slide down, add one of those per week, until you're ready for another plate. Then after a week with the other plate, start adding the little 5lb add-ons as before week by week.
If the machines don't have those add-ons, find a 2.5kg, (4.4lb), disk and a spare pin and tag the weigh onto the front or back of the machine if possible, then the next week, add another plate and leave the disk off, then the following week add the disk back, then another plate and no disk the week after that etc etc.
In the case of getting a trainer, when you use a trainer, you will probably sub some of the machine stuff for other more free weight stuff. As I said, I am adivsing against things they may do for now, as some of the exercises I think they'll use, can require things like two or more movements in one repetition, or an unusual stance, where more than one joint is bent and because of this, if one aspect of those exercises isn't right, like a Bent Back, Elbows locked out etc etc, this can cause issues.
The things I suggested have a basic sit or stand approach, with a basic range of movement, so no fiddly things to master. This should give you something to work with, until you can switch some of the exercises for other free weight stuff under supervision.