You should know at least basics. There was no “Hungarian Empire”. Croatian noblemen were vassals to Hungarian king as well as Hungarian noblemen were vassals to the same king. Hapsburgs were elected by Croatian Parlament in 16th century:
Vassal is vassal.
https://en.wikipedia.org/wiki/Election_in_Cetin
Serbia was a non-existing entity during the Ottoman occupation. During that period the “Serb” ethnonym was hardly mentioned. All Orthodox people in the Empire were called Rum, which means (Byzantine).
https://en.wikipedia.org/wiki/Rum_Millet
False and irrelevant. What name Ottomans used to call occupied territories was for their own usage and have had no influence on ethnonyms. Ethnonyms have existed among Serbs as well as among other people on occupied territories such as Albanians, Bulgarians...
There was no “Hungarian army at our back”. Hungarians were hardly managing their own kingdom. Ottomans managed to take Buda (Hungarian capital), almost Vienna, but never Zagreb.
See highlighted
The Croatian troops were led by the Ban of Croatia, Thomas Erdődy, and major forces from the Duchy of Carniola and the Duchy of Carinthia were led by Andreas von Auersperg, nicknamed the "Carniolan Achilles".
I am talking about facts. Glorious Serbian fightings against Turks were more a myth then a reality. On Kosovo Battle there were also Croatian and other foreign units fighting on the Serbian side. One of them was John of Palisna with his Knights of Saint John:
The bells were ringing in Notre-Dame...
Would it be disrespectful to mention that some Serb nobility refused to fight as they were in peace with Ottomans.
And?
Some Serbs also escaped (Branković) during the battle and left Bosnians to continue the fight.
That was a myth.