FYI. this is a scripting issue and not a 2D specific issue so should be posted on the Scripting forum. Regardless, when you post code, please use code-tags (you can go back an edit it too) because a wall of plain-text is difficult to read. Also, when you get an error, also state what line the error is on.
As to your error, a quick look at the API docs would reveal your problem so that’s something you should try to do in the future to keep you moving forward. C# is case sensitive so it’s Bounds.Expand and not Bounds.expand. It’s an easy mistake to make but if the compiler doesn’t understand it then it’s either mispelt, has the wrong case or just doesn’t exist.