Garcia, 22, was shot in the head outside a home in the 5000 block of Silverado Drive on Sept. 1. Police are still searching for his killer, described only as a light-skinned black or Hispanic man in his 20s who fled in a late-model sedan.
Ron Marlette, spokesman for the Garcia family, said speakers at Tuesday's memorial will include Mayor Harry Price, Fairfield-Suisun Unified School District board president Chuck Wood, and Assemblywoman Lois Wolk, D-Davis.
Representatives from the offices of U.S. Sen. Barbara Boxer, state Sen. Mike Machado, D-Linden, U.S. Rep. Ellen Tauscher, D-Alamo, will also attend.
Garcia's father Raymond Courtemanche, his sisters Brianna and Tearae, and his grandmother Chris Garcia will present eulogies, Marlette said.
The seating capacity of the football field and the gymnasium is 4,000, and the campus will open for seating at 3 p.m. The school is located at 824 Washington St.
Early arrivals may line up at 2:30 p.m. for seating inside the stadium, city officials said. City Hall will close at 3 p.m.
Garcia's casket will arrive at the high school on a fire truck, Marlette said. A private burial is scheduled at Fairmont Memorial Park in Fairfield after the estimated 90-minute memorial service at the high school where Garcia graduated in 2004.
The service will include photographs of Garcia on a huge "JumboTron" screen and the release of 36 doves, Marlette said.
Teen singer Holly Stell, dubbed the "Petite Pavarotti", is flying to the Bay Area from Europe and will sing Amazing Grace, Marlette said. Police said Washington Street, from Texas Street to Louisiana Street, will be closed to traffic.
Parking will be available on streets surrounding the high school and at off-street facilities including the First Baptist Church, the Solano County juror parking lot, the Solano County parking garage, the city of Fairfield parking lot and at the Masonic Lodge.
More parking information is available on the city of Fairfield's Web site.