they didnt really teach us much than by the book when i studied. i ended up with my client i got on my first year paper being female, almost 50, chronically overweight with sky high bp. my tutor used to get annoyed with me as i walked her instead of gyming her while i waited for the doctors note. he also had a go at me for not pushing her hard enough when i did my assesment. she was white as a sheet and didnt look well compared to how she normally looked and had told me she wasnt feeling well when i asked her. he was away taking a register at the time so missed that vital bit of info. it still may pay to get someone to do you a simple program as it will be a general full body and they should work all the muscle groups. anything that is hard to do, that you feel may injure you, refuse to do. i still refuse to do anything that hurts me in a bad way. being old LOL we can put our foot down and have a hissy fit and just say no! my trainer btw has been in the industry for prob 15 odd years. he has studied but just to get the bit of paper and he also has worked alot with people with injuries so we do lots of prehab and he also knows how to work around injuries.
i always avoid machines myself for the whole body movements like squats. i do use them for things like leg press and stiff arm push downs and i use cables. you got your swiss ball didnt you? i'd practise squatting with that till you get the form and then just do the bar till you are able to add weight. i wouldnt even stress how much weight you can or cant do. just do it and concentrate on form. you can use light dumbbells for alot of stuff. barbells generally weigh 20kgs but some are only 17kgs.