Dear Michelle, welcome to our Forum!
I suggest you to write in English, or both, in translation and English, so we could be sure what are you searching for.
The main question that we were researching was to find Church records for Mrzlo Polje, which belonged to Parish of Močila (according to
Shematism of Serbian Metropolitanate of Karlovci from 1905, which was published in 1910).
I tried to find these records on FamilySearch.org, but without results (there isn't parish of Močila on the list). Maybe the both, Mrzlo Polje and Močila were part of some other parish in the 19th century, but that could know someone of members that know better this region.