If you don't have rock in the tank yet, then you aren't going to be able to complete your cycle. you need aerobic and anaerobic bacteria (bacteria that likes oxygen and bacteria that doesn't like oxygen) thriving in your tank. This is the whole point of the initial fishless cycle, to get the bacteria up and running to cycle the ammonia that will occur naturally in your tank from fish waste and other stuff. The bacteria that likes oxygen will live on the surface of the rock and sandbed if you choose to have one) where oxygen is plentiful, and the bacteria that doesn't like oxygen will live deeper inside the pores of the rock and deeper in the sandbed.
Edit: just read a little bit better. you have some rock in your tank, but you want to seed it with live rock. All I can say is that pick your LR wisely. Biodiversity is good, but there are things that you do not want in your tank. some things you will not be able to see, such as spores.