What level do you start to translate passages? Thanks!
When you feel ready and have access to material at an appropriate level.
When I started Duolingo, the system kept encouraging me to start using Immersion once I had reached about level 6 or 7. I waited a bit, but not too much later - but I also had done quite a lot of work in Spanish years ago, so I may have been better prepared than someone else at a comparable level.
I don't assume that all participants have access to Immersion since most/all people who started within the last however many months don't. If you don't have access to Immersion, you may or may not have local access to newspapers, library books, textbooks, etc. in the language you are interested in.
Not everyone has access to immersion, sadly. Duolingo's business plan used to be based on Immersion, but it isn't any more, and they seem to be gradually getting rid of it. Have a look at this post, which gives some more detail about what's going on, and some options for what you can do about it: https://www.duolingo.com/comment/16080760.