Je veux détecter tout seul les problèmes techniques, d'artefacts, etc.

Hi Anthony, 

Thanks for asking. You will find a few examples by utilizing the search field in this forum. Just type in the subject you will like to learn about, for example noise/grain, artifacts, color fringing, technical issues, and so on. That is one option. 

The other option is to join us on the forum. Follow the contributor critique forum. Try to answer questions the way you can, and select "Email me when someone replies". You will get all the answers we give and you can learn from them. The platform is where I learn.

The other option is to upload images here when you get a rejection and see what you can learn from each one.

As regards a formal course, I do not know of one. Possibly there is none for the time being. 

Here is a foundation you can start off with 

https://helpx.adobe.com/stock/contributor/help/submission-guidelines.html

https://helpx.adobe.com/support/stock-contributor.html

https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html?set=stock--fundamentals--adobe-stock-contributor

https://helpx.adobe.com/stock/contributor/help/editing-dos-and-dont.html

If you opt to join us on the forum, these should give you a foundation of information that will allow you to answer some questions. This is the foundation I started with. You may also search in this section for other relevant topics.

I hope you found this helpful

Best wishes

JG