"my_int" is the name of a variable. A variable is a storage location in memory that holds some value (whether that's a number, a string, a collection, object, etc.). A variable can usually be named whatever you want as long as it doesn't match one of the language's keyword/operators (these vary by language), and you can perform operations on.
The = sign in this case (and most languages) is known as the assignment operator (which is different from ==).
The value 7 is..well that's an integer value of 7.
Assignment works in the way it shows: assigning the integer value 7 to the variable named my_int.
I highly suggest going through an actual course / tutorial set or even a book to learn a programming language for the first time. Learning from an amateur programmer (sorry zaka, but yes you're an amateur unless you're doing it professionally
) can be bad, as not everybody does things the same way, and sometimes amateurs get into bad habits (even I had bad habits that I always try and work away from while developing at work). https://en.wikipedia.org/wiki/Python_(programming_language)#Use
And on the CodeAcademy page I've referred to it also says this in the description of the tutorial: "Learn to program in Python, a powerful language used by sites like YouTube and Dropbox"
Documentation can be found here that details what the language consists of (functions, operators, etc.): https://www.python.org/doc/
With every programming language...yes. Especially if you don't know any programming - then you have to start with the absolute basics of programming and understanding software development.
Any text editor, particularly one that supports Syntax highlighting for Python files (extension of .py).
