What it means is that no German can be forced by the government into a job, education or place of work. So for example, the Government cannot come and say "we are short on railroad workers, the next 200 graduates of this school will report to Hamburg Station for training and become rail workers in Munich".
That might be blindingly obvious today, but when this was written, the government that had just ceased to exist had heavily dictated who was allowed into which profession, not on personal qualification, but on things like faith, nationality, heritage and skin color. And other governments forming from the ashes right next door were indeed not capitalistic and their socialist central planning meant that they would direct at least parts of their workforce which jobs to take and sometimes even where.
In contrast, in Western Germany, whether or not one becomes a rail worker, which company educates them and where they work in the end is their choice.
Obviously choices are limited by reality. I can choose to be a railworker on an island in the North Sea, but I will be unemployed, because there is no rail line there and I won't get a permit to build my private one.
I can choose to study philosophy, but if I cannot find an employer in need of philosophers, I will have to fall back on making money driving an Uber.
I can choose to become a Pilot. But I will have a hard time finding a spare 747 to train on if I don't train with one of the big airlines. The may have their own, totally capitalistic goals. For example, contracts that say "if we train you, you have to stay for X years and work for us or pay X amount of money" are totally normal and legal in those businesses. And if their training center with the big 747 simulators is in city A, I can choose to train in city B, but I will obviously fail their program.
So no, this law does not imply any kind of automatic success on a personal level. You still need to qualify for the training you want, be able to pay rent in the city you want to live in and find an employer that employs you, or customers to become a successful freelancer. Maybe you cannot do that for personal reasons. But the government will not dictate instead. You are then free to choose the next alternative.