Zen meditation is quite similar to Theravadin in some ways, although not necessarily from the outside.
which tradition of Zen is it the teacher is from? and which country?
There is Dharma Wheel our sister forum for Mahayana and Vajrayana which maybe more useful for you considering you are going to be studying with a Zen Teacher, but I am sure members here can help relate what you are practising to the Theravada practices if that is what you are interested in.
Theory is useful, but more so when it is backed up with practice.
Blog, Suttas, Aj Chah, Facebook.
He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them.
But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion …
He must be able to hear them from persons who actually believe them … he must know them in their most plausible and persuasive form.John Stuart Mill