When you say that one month's special instruction belongs to personal trainer training, of course it is paid service. Just like tutoring, a large class may cost 100 a month, but one-on-one tutoring is a class 100.
If you just want to exercise, there is no need to find a personal trainer. Those instruments are quite simple. If you want to lose weight or exercise muscles in a short period of time, then personal training is definitely more professional and faster.
But it's usually not necessary.