Sorry, I know I'm not the first English speaker to be confused by perfect tense, but I'm not sure when to use any of these three. I get the difference between the first two, cause one could mean "I used to" instead of "I was". But I threw "I used to work" into Google translate and got the third one.
I also live in Texas, so I'd like to make sure I don't sound too weird to native speakers in the area. I read "coche" in a book, and spoke it once in a part in the world where they say "carro", which everyone thought was pretty entertaining haha. Apparently they don't use past perfect here either