Use the 'irun' utility provided by cadence.
it will pick up the files as per extenstion and compile them.
You need to mention -sysc option alogwith irun on command prompt for systemC.
Now you can use verdi to dump waveform without write any sc_trace. it is just like using $fsdbdump in verilog, just point the starting point and level you want to dump.
for how to simulate or co-simulation, I belive the cdsdoc has fully document the detail.
if you are using pure SystemC right now, maybe you do not need ncsc since it cost license fee. it was said the the native compiler of ncsc is faster than open source version, but it may lack of debugging GUI like VC.