I would like to know some starting moves (20 and 70 frames) that give me some kind of advantage by dodging the most usual starting moves and setting up a favorable situation for second turn.

Everyone would.

Dodging usually comes only if you got lots of luck, you can't know what your opponent is going to start with... best defense is a deadly attack! :P

But if you wanna try, contracting knees and contracting hips or (extending hips + extending abs) should work