Yup so you absolutely need to see that ammonia spike. The live rock that you initially added should have been uncured so that it jump starts the cycle. The dead crap on the live rock is what causes ammonia to rise. Definitely do not do any water changes when your cycling the tank. That just slows down the process even more. Don't worry about testing pH. You can test nitrite if you want but your main focus should be accurately testing the ammonia and nitrates.Before adding anything else into the tank besides the 2 clown fish and the rock and sand, tested the water every other day. Nitrites and Ammonia never went above 0. The PH never changed from 8.2, and the nitrate would sometimes maybe go to 10.... but after a water change it was back at 0. So I figured it must of cycled.
After your last couple of posts, I don't think it was really the 9 lb's of new live rock that killed everything anymore. Now I'm 99% sure your tank never cycled and that was the cause of death (due to an increase in ammonia when adding the fish).
In regards to pet store advice. It's pretty much something every new reefer experiences. I had a bunch of fish store experts tell me this and that was the cause of whatever problem I was experiencing. It wasn't all bad, some of it was good solid advice. But I would just advise to ask questions online before you drop cash at the lfs/petco. It might be a cynical perspective to take, but at the end of the day, the lfs/petco is there to sell you stuff.
Chances are you probably won't even need to make a thread for many of the questions you might have as a beginner. The same questions have been asked and answered hundreds of times before and a quick google search usually gives you alot of insight.
Can you post any pics of your setup?