I was born and raised in Estonia, to a Russian-speaking family. I had subsequently immigrated to the United States for a graduate degree after finishing an undergraduate degree in the UK. I am well versed in both technical and scientific Russian language applications, as well as colloquial Russian. While I do not possess academic level experience in teaching Russian, I have helped a number of close friends to improve their Russian language skills, which included both, beginners and advanced speakers.
Russian language is notoriously hard to master due to quite complicated grammar and spelling in particular. That being said, with enough practice, learning to speak and understand Russian is quite doable.
Unlike most other locations in the country, Miami does actually have quite large Russian community, so finding people to practice verbal Russian would not be hard.