If I've got only two days for the gym per week, should they be consecutive or not for best results? Thanks
Your muscles require exercise followed by rest and recovery in order to promote muscle growth. Too long or too short of a recovery period and they won't adapt (i.e. get bigger).
Going only two days a week to the gym, the best bang for your buck would be a full-body workout on two non-consecutive days minimizing the rest time between both workouts. Think Monday and Thursday, Wednesday and Sunday, etc.