This should definitely be in your maternity book. You need to look in the postpartum area under uterus and lochia - Use your index if you need to. If it isn't in there, that is a bad choice on your instructor's part.
About 1 hr after delivery, the fundus should be firm and at the level of the umbilicus. The fundus continues to go down into the pelvis about 1 cm per day and you should not be able to palpate it 14 days after giving birth. You should encourage your pt to void BEFORE palpating the fundus because a full bladder could displace the uterus.
Since the fundus should be firm and at the level of the umbilicus about 1 hr after delivery and will start decreasing about 1 cm PER DAY, you would expect the fundus to be at the level of the umbilicus 2 hrs postpartum.
First few days after birth, the lochia is lochia rubra, which is red and clotty. There should be less blood each day and it should lighten in color. It next goes to lochia serosa, which is brownish-pink. Finally, it goes to lochia alba, which is white. If they are quickly saturating the pads (e.g., saturating 1 pad in less than an hour) or large blood clots can be something more serious like hemorrhage. If the fundus is firm but there is a lot of lochia, this could be something serious as well.