dear Justyna,
Every country has its own rules and regulations to becoming a paediatric physiotherapist ( from nothing at all to 4 yr parttime postgraduate education). On the wcpt forum I have listed the names of the paediatric physiotherapy societies I know of, you could possible ask them what kind of courses they have in their countries.
(inter)national pediatric PT groups
In many countries foreigners are allowed to follow the courses... I suggest you go to my site and have a look around. I have done a few in Switzerland. You will find a lot of information which you might might find informative and which can help you along.
good luck with your study
Esther de Ru
www.estherderu.com