I am going to be travelling through the western Balkans (specifically Slovenia, Croatia, Bosnia & Herzegovina, Montenegro, Kosovo, Macedonia and Albania) and would like to learn some of the spoken languages. As I will only be spending a matter of weeks in each country, I imagine would best to learn some of the common features of the languages and continue to learn as I go.
Despite its occasional innacuracy and over- simplification, I learn very well from Duolingo. However, they don't offer courses for any of these languages. I am therefore looking for languages that are similar (in all senses that are important for a little learning and conversation - words, grammar, alphabet etc.) to those in the South-Slavic group. I realise that there are some massive differences within the group anyway (e.g. Latin vs Cyrillic) so this is not the ideal approach, but I think it will be fine for my purposes.
The available languages that strike me as having potential for high linguistic similarity are Romanian, Hungarian, Polish, Russian, Greek, Czech, Turkish and more likely Russian and Ukrainian. Which of these (if any) would be a good bet? Are there any other resources that do offer South-Slavic languages that might be better?
I am not someone to whom language learning comes particularly easily and don't have much time to do so, so I'm only looking to go to a basic level. I am a native English speaker and also speak Italian to an intermediate level.