start with being born in a slavic country, then find the differences between russian and your language
just swap around the colours in your flag
Maybe the first one would be talking coz Writing is not that important as speaking so if ur going to use that only in CS then go for speaking only by hearing and learning.
same as with any language bro, immersion above all else. also start from simple things, don't try to get good from the start, doesn't work like that. learn "baby russian" and pracc with someone from CIS be it a friend from Steam or actual guy/girl that lives in your country
if you want it to use only for CS, start off with learning words. One by one, when you feel you are ready, move on to constructing sentences
Try and not focus on the Grammar at first. It's hell for foreigners.