You can do both, but you need to know a few things first..
Planes with rudder and elevator typically have a lot of dehidral at teh wing joint. Not to mention are typically a 'high wing' airplane. With lots of dehidral, the plane tends to right itself. It's a typical thing of trainers, to have big dehydral, as it offers a self righting airframe. The rudder tends to 'kick' the tail in the desired direction, initiating the turn, and teh plane will then level out to a level (neutral) attitude once the rudder input is neutral.

If you don't have dehydral, or at least very little (typical of most low wing airplanes)*, you'll need something to help bank the airframe for a turn, typically done with ailerons. Once the plane has banked, the elevator can be used to pull into the bank, causing a turn. But the more you bank, the more you'll slip sideways (side slip) and will most likely need a bit of 'up' once the turn is made. The nose will tend to start to dip down durignthe turn.

As for eh CG, it's typcially 30 - 35% of teh MAC - mean average chord of teh wing.. that is, if it's a constant chord wing (straight, no taper or sweep) it'll be about 30 - 35% of eh total wing width. For tapered or swept wings, you have to do some math.. I can't remeber most, but you need to find teh average middle of the wing by adding the root chord to the tip chord, and then adding diagonal lines from the LE tip the E tip, and visa versa, where they cross will give yo the MAC...

I'm sure some else can sound in with the theory and practice. You might want to look in teh 'Aerodynamics' forum as well for this particular subject. And a plane is always more stable being nose heavy - slightly nose heavy.

*Most airplanes have some degree of dehidral. Most 'stunt planes' (Caps, Extra, Sukoi...) semingly have none. But do have a slight agle on the underside of the wing. That's why these plane 'defy normal physics' when flying.. and are considered 'harder to fly'