如何在Mapkit的其他位置用蓝色圆点显示用户的位置?

I'm a newcomer of swift 3 & Xcode 8, and this is my first time to ask question here. I want to set several pins in a Mapkit, and I also want to add user's location in the same Mapkit simultaneously. Furthermore, I hoped that the center of this Mapkit is a specific location instead of user's location. However, I faced a problem. I'm a newcomer of swift 3 & Xcode 8, and this i