I am new in game developing and I decided to study unity to be my foundation in game developing…Can you please help me what do i have to learn first…? 
First of course no one how new you are.
If you have a background in any game creation whether it be the elder scrolls construction set, RPG maker, Game maker, FPS creator, or even WCII world editor you already are not a complete noob.
First visit the begining videos and learn how to get around Unity’s interface, then download one of the great tutorials they have setup. Then from there you will know how to import 3d models, and how to make basic games. Once you have started assembling things for your games as you run into problems search the document sections, google problems, check answers.unity3d.com and you will almost always the answer to lots of problems. So basically dont be afraid and dive deep your imagination will take you the farthest.
-Naison
this is my first time that i will make my 3d model, scripting and etc… anyway, thanks for the advice. 