[2] He played basketball for Christ the King Regional High School in Middle Village, Queens in New York City.

As a junior, Alvarado averaged 17 points and 6.5 assists per game and was named Catholic High School Athletic Association (CHSAA) Player of the Year.

[4] In his senior season, Alvarado averaged 17.9 points per game and led Christ the King to the CHSAA intersectional quarterfinals.

[6][7] On September 15, 2016, he committed to play college basketball for Georgia Tech over offers from Rutgers and Seton Hall, among others.

[8] Georgia Tech head coach Josh Pastner had first seen Alvarado at the Nike Elite Youth Basketball League.

[15] On January 25, 2020, Alvarado scored a season-high 26 points and recorded eight rebounds and a school-record nine steals in a 64–58 victory over NC State.

[16] In his junior season, he averaged 14.4 points, four assists, 3.4 rebounds and 2.2 steals per game and was named to the Third Team All-Atlantic Coast Conference (ACC).

[18][19] Alvarado passed on gaining an additional year in college due to COVID-19 game cancellations and declared himself eligible for the 2021 NBA draft.

The incident received press coverage after Embiid praised Alvarado and paid the $2,000 league fine associated with it.