Burj Khalifa can be easily accessed by the Dubai Metro. Take the Red Line and alight at Burj Khalifa/Dubai Mall Station. From there, you can take the air-conditioned pedestrian walkway that connects directly to the Dubai Mall, which is adjacent to the Burj Khalifa.
Taxis are widely available throughout Dubai. Simply ask the driver to take you to the Burj Khalifa, which is a well-known landmark. If you prefer driving, Burj Khalifa is accessible via Sheikh Zayed Road. Follow the signs to Dubai Mall and Burj Khalifa. There are several parking areas around the Dubai Mall for those driving their own vehicle. Don't forget to take advantage of the valet parking service which is available at the Dubai Mall.
Dubai also has a public bus system that services the downtown area. Buses D03, F13, and others stop at the Dubai Mall/Burj Khalifa bus stop, which is very close to the entrance.
Using a ridesharing app like Uber or Careem is another convenient option. Enter your destination as 'Burj Khalifa' or 'Dubai Mall', and you will be dropped off at the main entrance.