Apple Park is still under construction, the Apple campus not being 100% ready for the employees to move in and start working there. The Apple company opened the center for visitors a few weeks ago and allows those interested to visit it, but more than that it is not accessible in Apple Park for the time being.
Apple has said that Apple Park will host employees this year, but it is unlikely that anyone will move there from the old campus until the end of this year. The numerous changes made to Apple Park have delayed the construction process beyond the normal deadlines established by the Apple company, so now the opening is still waiting.
Apple Park is Apple's most ambitious and expensive project so far, being also the most modern and technologically advanced headquarters of a company.
