A good portion (but by no means all) of the lead from the man will come through his left hand to the woman’s right arm; and it is important for the woman to be able to respond properly when the lead occurs. Keeping the proper level of tension in the right arm is important.
One of the most important places to take care of is your right shoulder. The elbow shouldn’t drop back behind the right shoulder; for a beginner you should focus on keeping the elbow in front of or at least even with the shoulder at most. Your elbow itself can move, up and down, side to side, but don’t let it drop back behind the level of your shoulder. If the man presses against your right hand and your whole arm collapses, this doesn’t allow him to properly lead you.
Keep that in mind and it will really help your following skills.