Well, problem solved.
Meanwhile I've found this tutorial:
http://nemops.com/prestashop-products-new-tabs-fields/#.Xn41onJCdhE
The script isn't realy working, but it helped me understanding how it works.
In addition with this list:
https://devdocs.prestashop.com/1.7/modules/concepts/hooks/list-of-hooks/
Needed hooks can be found...
At moment just strugling with showing content on displayProductExtraContent (nothing appears).
But I will solve that 😉
EDIT: Well, also this problem solved. Just reseting Module dosn't update hooks on front end. Needed to deinstall and newly install it...