A F# project does have some major differences from C# though:
The F# files are organized linearly, not in a hierarchy of folders and subfolders. In fact, there is no "add new folder" option in an F# project! This is not generally a problem, because, unlike C#, an F# file contains more than one class. What might be a whole folder of classes in C# might easily be a single file in F#.
The order of the files in the project is very important: a "later" F# file can use the public types defined in an "earlier" F# file, but not the other way around. Consequently, you cannot have any circular dependencies between files.
You can change the order of the files by right-clicking and doing "Move Up" or "Move Down". Similarly, when creating a new file, you can choose to "Add Above" or "Add Below" an existing file.