Cadets from all over the Alpha and Beta quadrants would apply and attempt to complete the four-year training program at Starfleet Academy, which would prepare them to join Starfleet.

The headquarters of Starfleet Academy were located in the Presidio in San Francisco, while the Academy training facility itself was located in Marin County across the Golden Gate Bridge. The training facility consisted of a Starfleet Command School, a Starfleet Flight School, a Starflight Tactical School, and the Starfleet Medical Academy.

Admission into Starfleet Academy began with the acceptance of the candidate's application. Once the application was accepted, the candidate underwent the Academy entrance competition exams, which determined those admitted by the best scores among a group of candidates competing to gain admission.

For more information on required courses and readings: https://memory-alpha.fandom.com/wiki/Starfleet_Academy_courses