Here are a few of the main characters, if you don't like the pictures you can imagine them as who you want.

Elizabeth Lestrange:

• 17
• Bellatrix's daughter
• Stubborn
• Smart
• Sarcastic

(This is what I imagine her to look like)  

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Lorenzo Berkshire:

• 18
• Lizzie's best friend
• Funny
• Really dumb
• Clueless 24/7

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Mattheo Riddle:

• 21
• Voldemort's son
• Toxic
• Short tempered
• Narcissistic

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Draco Malfoy:

• 18
• Lizzie's cousin
• Stupid

• Rude
• Sarcastic

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Bellatrix Lestrange:

• 43
• Lizzie and Cathy's mum
• Phsycopath
• Death eater
• Neglectful

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Tom Riddle:

• 19
• Lizzie's best friend
• Smart
• Secretly caring
• Protective

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Catherine Lestrange:

• 15
• Lizzie's younger sister
• Smart
• Trouble maker
• Sarcastic

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Aurora Malfoy:

• 18

• Draco's twin sister
• Never understands anything
• Stubborn
• Not independent at all

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Pansy Parkinson:

• 18
• Lizzie's friend
• Annoying
• Only exists for drama
• Dramatic

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

Theodore Nott:

• 21
• Mattheo's best friend
• Aggressive
• Stupid
• Impulsive

✿‧⁺˚*･༓☾✿☽༓･*˚⁺‧✿

That is most of the characters you will need to know there will be others like  voldemort mentioned a lot but I didn't want to scare you with his ugliness by putting a picture. There will also be other people but they are less important.