I so love Harry Potter and the JK Rowling books
Yes, The novels chronicle the life of a young wizard, Harry Potter, and his friends Hermione Granger and Ron Weasley
Yes,  and they have a wonderful friend in Dumbledore
Yes, is the headmaster of the wizarding school Hogwarts.
Yes,  They had to fight so many bad creatures
Order of the Phoenix (fictional organisation)
The Order of the Phoenix is a secret organisation in the "Harry Potter" series of fiction books written by J. K. Rowling. Founded by Albus Dumbledore to fight Lord Voldemort and his followers, the Death Eaters, the Order lends its name to the fifth book of the series, "Harry Potter and the Order of the Phoenix".
Synopsis.
Before the Harry Potter series starts – when the character Lord Voldemort declared war on the wizarding world – Albus Dumbledore,
Harry Potter
Harry Potter is a series of fantasy novels written by British author J. K. Rowling. The novels chronicle the lives of a young wizard, Harry Potter, and his friends Hermione Granger and Ron Weasley, all of whom are students at Hogwarts School of Witchcraft and Wizardry. The main story arc concerns Harry's struggle against Lord Voldemort, a dark wizard who intends to become immortal, overthrow the wizard governing body known as the Ministry of Magic and subjugate all wizards and Muggles (non-magical people).