Yes, the Tesla Model 3 can park itself. The Model S and Model X will get the same feature later this year.
Autopark is Tesla’s driver assistance feature to help you park. It uses surround cameras, radar and ultrasonic sensors to find an empty parking spot and park itself.
Autopark is part of the FSD package (Full Self-Driving).
Tesla Smart Summon
In addition to Autopark, you can also use the Smart Summon feature. With the push of a button your parked car will come find you anywhere in a parking lot. Your Tesla will leave its parking space and navigate around obstacles to its owner.