On new construction I test my waterlines with 170# PSI of air. On remodel jobs I just turn on the water BUT I have also been soldering for a long time and trust the work I do.
That said soldering jobs that don't leak with in a few days normaly won't, but then again your new at it. It's your house and you will be the one to tear up the floor or ceiling if there is a problem down the road.
Not sure if this helps or not.