I keep having doubts on whether I am pronouncing something properly in prayer. I listen to many people’s recitations and some of them different to one another. I don’t know what to do, or what’s the right pronunciation.

I recommend you listen to one of the well-known Arabic reciters of Qur’an, and do your best to pronounce like them. If you cannot fully pronounce the words as they do, do your best. Then later if you have any doubts, ignore such doubts. I would recommend Parhizkar. He is Shia