Hi, so i am learning Arabic because it is such a beatiful language - and also because my own religion is written in that language. So i wanted to ask you, when would I be able to start using Arabic letters and alphabet with confidence - after which level perhaps, if that is relevant?
...I do not know yet.
The course is currently Beta which means it'd teach you the alphabet and a few words & maybe sentences? idk.
I recommend you learn it from another source or at least read the posts on the forum that teach you grammar & stuff (thanks to anyone who's posting those! :D)
My advice is not to depend on Duolingo alone. As for the script or letters, you can at least practice writing in your spare time to let your brain get used to the shapes of the letters, and hence start reading faster by time. I see that you are probably a Turk, and I believe in Turkey there are great resources for both, Arabic and Ottoman Turkish (which was written in Arabic scrip variant). If you can reach or check such resources you can practice and enhance your writing and reading skills further (but note that Ottoman Turkish had maybe 4 extra letters more than regular Arabic for sounds not found in Arabic, like "G").
Bonus: There is a page on Facebook for Ottoman history and it posts many pictures of books and manuscripts written in Arabic or Ottoman. Check: Ottoman Imperial Archives.