Scene misunderstanding.

Need help guys!
i made a little video, so its easier to explain.

First i press on a button, so animation will play and the door is open. This is a simple canvas button with animation action.

Next im going to my previous level and returning back. The gates are closed.

What can i do, so Unity will save all the progress automatically?

Thank you very much!

 

There is no save mechanic in Unity because simply every game would require different solution.

You can just save your gate's last position and set it there if it is already opened on scene load.

 

Save position where?

 

There are a lot of solutions for that. I suggest you take a look into Unity's persistence tutorial:
https://unity3d.com/learn/tutorials/topics/scripting/persistence-saving-and-loading-data