Just started a salt water tank and got some bad advice, pet shop told me to put a clown fish in my tank. Needless to say after reading more about salt water tanks like an addiction I found out this is BAD. They have a no return policy on salt water fish (Petco).
What should I do now to try and make the cycling process the least stressful I can?
So far she is doing fine, swimming, eating ect... but it has only been one day. I did a 2 gallon water change today just in case.
Also I have the strips for testing and also found out these are junk

It looks like they show ammonia .25 and some Nitrate. (Before the water change.)
Here is the setup. It is a 12g nano with a mechanical filter (bio balls, carbon, ceramic things). I put 10lb bag of live sand in it and one cured live rock. And some plastic hiding ornaments.
After reading I decided to put the cured rock in there, it should jump start the cycling process and make it faster? right?
I also bought a 2nd cured rock and dry dead rock. The dry rock was dirty and after some reading I put it in a bin with a heater and a power head and 1 piece of live rock to cure it. Then I added some fish food.
I read it could take 1-2 months to cure. Once it is cure can I then directly add it to my fish tank with no harmful results? I'm trying to go from Fish Only to
FOWLR then maybe reef after that.
Also I couldn't find much info on a Fish Only tank. How often do I need to change the carbon? Anything I need to do or know? How often do I do water changes? Once my rock cures I will add that.
Thanks for any advice.