I believe that you are in Europe, yes? A lot of people's comments, including mine, are likely based in US experiences.
This is like the "apprenticeship" thread that is also recently here somewhere. This kind of stuff is few and very far between. It has gotten harder to do this over the past 35 years or so.
If a potter agrees to take someone on...... suddenly they are occupying some of their time in doing teaching/training. Since most potters are single person operations......... when they are tied up teaching..... they are not producing. Nothing is happening in the studio. So in a very real sense this is costing them money..... and that is BEFORE and ABOVE whatever wages they are paying that person.
Then there is the wages factor. In most places there are minimum wage laws to contend with. Some people try to skirt them...... but the risk if they get caught is astronomical. To skirt them legally is a real paperwork and word-smith game.. and is not easy to set up.
Then there is the liabilty factor. If a helper / assistant / apprentice gets hurt on the job..... the potter better have Workman's Compensation insurance. That stuff is expensive.
Then there are workplace laws that are supposed to be complied with. Organizations like OSHA have standards that DO apply. For just one example, since pottery involves clay, and clay has free silica content (not to mention glaqzes and such)... the controls that are supposed to be in place for protecting workers are pretty hard to comply with. As a single potter yourself, you can decide to just work in a pigstye....... but if you bring in an employee....... that has to change. Or you can be in BIG trouble.
When you get done with all of these kinds of considerations....... it is a BIG decision to take someone on. The fact that some people still do that often means that they are not really schooled in business practices... and often do not KNOW that they are exposing themselves to these kinds of risks and liabilities.
Then just when you get someone trained well...and they are actually creating a Net for you....... they decide to leave and go set up shop themsleves. And in some cases.... competing with you in the same market.
There are some folks that DO this well... and they are the "few and far between" folks.
To gain the education....... like for many jobs....... you likely will have to invest in it yourself. College, workshops, books, videos, shared/coop studios where you can observe others working, and so on.