Do you mean C# or JavaScript or when you C# or Java you just meant any Engine/Framework/etc?
I use Unity, I played around in a few other engines but it's what stuck. I was a dev for 10 years before Unity including C# through SharePoint so learning wasn't any type of problem. I had a really good book that explained the Unity quirks and it helped me learn it. I'd say 3-4 months before I jammed out my first game though even being a coder. Cuz just cuz I code doesn't mean I draw or compose hahahahaha