Join a boxing gym, hitting the pads and bag is great but sparring is where you learn how to box. One on one sessions would be good for someone after they have started to spar and compete so they know what to work on otherwise its pretty much a waste of time. Also I would have to question who is giving you the one on one coaching if they can't answer your question on where to find sparring.
It could be he is being trained by an old school bloke who doenst have contact with any of the new gyms but i would also be a bit suss if the bloke didnt know where i could get sparring @.
The gym I go to have boxers, but the timings don't suit me so that I can go there and spar with any one of them. I am either at work or coming back from work when the gym closes and that is why I have to do a one on one with a coach otherwise I will never make it to the gym's boxing timings. Thanks for your comments.
you could see if they do sparring on the weekends, usually when a fight is coming up there is extra sparring and its usually on the weekend. Best of Luck