I would clear all debts my parents have. They make so much money every year but countless credit card bills and insurance fees cancel any profit they should be making.
Give each of my parents 500,000 and my siblings each 100,000. Put a bit over half of it in the bank, buy equipment to build a recording studio to make music, a sick car, a new laptop + other random cool things, and id donate the rest to charities of my choice. Oh, and id invest some of it too.
I'd buy a $500k house in some extremely hot place like Arizona, a bugatti and save the rest. I'd still study because I really want to become an orthodontist