Fender strat body, how to set up the job

OK so I know nothing about cnc machining other than what I’ve learned in the last 4 weeks , no hands on training.

So my question is, if you want to machine a job and don’t want your material to have to be set all the way at the bottom left corner of the waste board the only way to do that is to set the datum in the center of the material and then mark your material and set the bit exactly at that point and zero x and y , the Z can be zero to the waste board or material surface depending on how you set up the job correct? But if you create the job with the left bottom datum you have to place your material in bottom left right?