[3] Arriola attended Mater Dei Catholic High School in Chula Vista and iHigh Virtual Academy in San Diego.

[8] Following the 2012 season and despite being offered a professional contract by the Galaxy, Arriola opted to sign for Club Tijuana of Liga MX, the highest level of soccer in Mexico.

Arriola was part of a string of American-born players to join the Xolos including Edgar Castillo, Herculez Gomez, Joe Corona, and Greg Garza.

The decision allowed Arriola to live on the United States side of the border with his family but cross it for training and matches.

[10] On July 19, 2013, Arriola made his professional league debut in a 3–3 draw with Club Atlas to open the 2013–14 Liga MX season.

On August 9, 2017, Arriola signed for Major League Soccer side D.C. United for a club record fee of $3,000,000 plus allocation money for his rights to LA Galaxy.

[13] He scored his first goal for D.C. United in their season finale, and last game in RFK Stadium on October 22, 2017, against the New York Red Bulls.

On July 14, 2018, in a 3–1 win against Vancouver Whitecaps, Arriola scored a personal record two goals for United in their inaugural match at Audi Field.

D.C. United would also retain 30% of any transfer outside of MLS, with an additional $300,000 in General Allocation Money if Arriola reaches certain performance-based metrics.

[28][29] Arriola made the United States U20 squad for the 2015 FIFA U-20 World Cup, appearing in four of the team's five matches and scoring a goal in a 4–0 rout of hosts New Zealand in the group stage.

Arriola scored his fourth international goal in the opening game of the 2019 CONCACAF Gold Cup against Guyana at Allianz Field in Saint Paul, Minnesota.