The balance point first (most important). I would project the point on the plans up to the top wing and us that point to balance from, just lift it with finger tips at each side at the point above shown on plans. I usually use a jig that I build using two dowels with those pointed ereasers on the end (better than your fingr tips) level by eye.

First flite I would set controls so Elevator was about 1" Rudder 1.5" and ailerons 3/4". Use dual rates at aprox. 50% of this.