Really sorry about your clowns, it might be brooklynella that got them. It is a white filmy disease and is pretty fatal if not caught and treated, which to be honest i'm not quite sure how you would treat it as I have been very lucky.
If you like a challenge and enjoy your tank don't give up! It sometimes takes a while to get the hang of things salt, but just read and research every question you have and you will get it.
The people on this forum are awesome and if you ever have any questions feel free to post a thread and we will all be ready and willing to help.