In an unusual step, Ryan Routh, 59, is representing himself at the trial in Fort Pierce, Florida, which is expected to last between two and four weeks.
The Hawaii resident, who has no legal training, is charged with the attempted assassination, assaulting a federal officer and firearms offenses. He faces life in prison if convicted.
Among his bizarre attempts to prepare for the trial, Routh has requested strippers and a golf putting green while in detention, according to US media.
The demands — as well as Routh’s request that jurors be selected according to their views on Gaza and Trump’s desire to purchase Greenland — have been rejected by the court.
Routh was arrested on September 15 after a Secret Service agent saw the barrel of a rifle poking from the bushes on the perimeter of the West Palm Beach golf course where Trump was playing a round ahead of the November election.
The agent opened fire and Routh, who fled in a vehicle, was arrested shortly after.
The incident came amid heightened security for Trump in the wake of an assassination attempt on July 13, where 20-year-old Matthew Crooks fired several shots during a rally, one of them lightly grazing Trump’s right ear.
The attack, in which a rally goer was killed, proved to be a turning point in Trump’s triumphant return to power. Crooks was immediately shot by security forces and his motive remains unknown.