1)what is the difference between with wait state and with no wait state(read/write)?what are the advantages of both in APB?
There isn't any advantage as such; use a wait state if your periperal access timing requires it, or don't use a wait state if you don't need one.
The original APB releases did not have a PREADY signal, so all APB accesses took 2 PCLK cycles, so the "setup" phase when the peripheral would see what transfer is being requested, and then the "access" phase when the peripheral had to perform that requested transfer. For virtually all peripheral designs this should be easily achievable as we are not looking at complex peripheral structures like memories where multi-cycle access timings might be needed.
However there were requests that the "access" phase could be extended, perhaps for more complex designs than the APB protocol was originally designed for, so AMBA 3 APB added the PREADY signal (as well as the PSLVERR response).