I don't have Arduino Manager, It cost $6.99
. Please take my answer with salt.
1. Do I still need any Shields or Ethernet shield If I'm already using Arduino yun? In the documentation it says it's required but yun has ethernet port.
A: No, Ethernet shield or wifi Shields is not needed.
2. Since im using YUN, the software that I need to upload to Arduino is TestArduinoManagerForYun Right?
3.Can I use Arduino Manager without using the Ethernet Cable? I already can upload sketch thru Wifi.
A: Better upload sketch thru USB port. No Ethernet Cable is needed.
4. In the "TestArduinoManagerForYun" sketch, there's no part of the sketch that I need to put my IP Address or MAC, does it mean I don't need to?
A: You could get IP Address from Arduino IDE.
5.Aside from the port number, Do I need to edit TestArduinoManagerForYun to make it work?
A: suppose nothing.