To beat malfoy easy the average person gets to him at lvl. 25-30. I'm at lvl. 32 before the Whomping willow because at the start go into every magical encounter (battle) to get all the exp. You can get. You'll beat the giant rat easy if you always battle you should be at lvl. 45-60 at Malfoy and he is lvl. 60. Bye.
First what you do is go to the fourth floor and go to the wall that is firthest South (up) then go right and you'll find a opening which is the hospital wing andgo in there and you'll see Madam Pomfrey. Talk to her and she'll say " Hello! How are you feeling?". Then she'll say " You look injured. Here, let me help you and she will heal you.
At the beginning of the game,when you are in the cellar,fight all the enemies with the same spell and soon it will level up so keep training until the spells are leveled up to level three so keep training until then or when you get tired of doing so.