[2] He began playing basketball at age 4 but did not join a youth league because he found them unruly.

[3] When he was in fourth grade, his family moved from Fresno back to Orange County, living in Yorba Linda, where he reached out to a local club team.

[5] On January 16, 2015, during that season, he made a buzzer-beating three-pointer to defeat El Dorado High School.

[6] As a junior, Okpala averaged 23 points and 8 rebounds per game to lead Esperanza to a conference title and win Crestview League Player of the Year honors.

His most notable moment in that year was when Okpala dunked on Trevor Hooks of Orange High School.

[4] On November 25, 2016, Okpala tallied 41 points in a 76–59 win over Spartanburg Day School at the Tournament of Champions.

[4][8] On March 26, 2017, Okpala led Esperanza to its first California Interscholastic Federation (CIF) Division II championship, scoring 22 points versus Moreau Catholic High School.

[15][16] On March 3, 2018, Okpala recorded his first double-double, tallying 18 points and 10 rebounds in an 84–83 win over Arizona State.