Family and friends of Kiyan Prince filled the Seventh Day Adventist Church in Holloway, north London for a service to celebrate his life on Thursday.
Pallbearers carrying the white coffin passed through crowds of people forced to stand outside the church.
A two-minute silence was held at the London Academy to mark the start of the funeral.
Head teacher Phil Hearne said Kiyan was an "almost eccentric" character who was known and loved by staff and students alike.
"He was a beautiful young man, the kind of which in 22 years in schools I have never seen before," he said.
"It did not matter to him anyone's age or religion, whether they were black, white or Asian.
"If they needed help and he thought he could help them, he did his best."
Gary Waddock told the official QPR website
'I thought the words spoken by Mark (Kiyan's father) summed Kiyan's whole life up. He spoke of Kiyan's beliefs and his caring nature for other people, no matter what age, religion or race they were.
"He emphasised the fact that young people will be more successful in life if they have a focus and desire, and that Kiyan's life should be a demonstration of how this can be achieved.
"I hope everyone who attended the service will have taken something from it, especially our young players and I hope they will realise that with a determination, desire and belief, anything is possible.''
Kiyan Prince R.I.P.