It is hard to say without actually seeing the bass, but my guess based on your description of it is that there is currently too much relief (ie: forward bow) in the neck now. I find that is typical with most factory or music store setups (or complete lack thereof). As mentioned above, I like to run my necks almost dead flat, with just a slight bit of relief between the nut and the 7th fret, and with the frets shaved for a "fall away" from about the 15th fret or so to the end of the neck.
Also, given the type of bass you said this is, I suspect that it could use a good fret shaving / levelling and redressing to get rid of any buzzing.. so... basically have a good reputable guitar tech check it out and then pay for a good fret levelling, redressing, and a complete setup including adjusting the action to where you want it . This will probably involve filing the nut grooves to the proper depth or replacing the nut if they are too low now, adjusting the truss rod for the proper amount of relief, adjusting the intonation, etc.. You teacher may be a great teacher but may not be a very good or knowledgeable guitar technician (no insult intended in any way....).