So I have found out how to draw borders, that's finished. The map should have around 140 provinces.
I now also understand what to do to change unit images and flags, although I'm pretty bad at drawing so I will have to find them somewhere and add them in a mod.
12 Factions have been added: Serbia (I had to add my own country, sorry

), France, Poland, Germany, Mongols, Byzantium, England, Fatimids, Castille, Seljuks, Sicily, Algeria
But there is still one problem I can't solve: Adding provinces. I read instruction several times, did everything according to them, but when I click to add new province, nothing happens. Is there something I missed? I need help about this one, I can't progress until I solve this