Although Serbian is similar to Russian, it is still a different language, and in order to be able to express yourself at least at the everyday level, you need to study it. By the way, the Montenegrin language is essentially the Serbian language with only very small deviations. For example, instead of "river" they say "rijeka", "lepa" - "liepa", i.e. "e" is replaced by the letter combination "ee". That's the whole difference.
Here is a very good one Serbian tutorial: http://roman-dushkin.narod.ru/projects/srpski/
And on this site Let's learn Serbian together you can download dictionaries, audiobooks, and Serbian tutorials.
Personally, the dialogues in Serbian, the so-called “matrices of the Serbian language” help me a lot; a link to them can be found here - http://serbianblog.ru/?p=20
So stick with me, friends! 🙂