If I want to move say 11July 30 and the stock is trading at $28 at the moment (out of the money) over to say 23 Sep 30, how would I do that? Do I pay more or the same?
There are several good books about options trading worth reading if you are just starting out trading them.
Here's one I liked: The Option Trader Handbook: Strategies and Trade Adjustments by George Jabbour & Philip H. Budwick
If I want to move say 11July 30 and the stock is trading at $28 at the moment (out of the money) over to say 23 Sep 30, how would I do that? Do I pay more or the same?
You pay more (assuming the fwds are the same)... All else being equal, the price of the option always (or nearly always) increases with time to expiry.