How do I make a file that has the user's data

How do I make a file that has the user's data, level weapon attack ... and that the player can upload that file to another computer

I am working on this as well and learning of saving. I would suggest using instance variables andd then pointing those values/strings to a save function, and then load function when requested. I know construct actually saves quite a bit of information with the built in save, but I would still do variables for thins like this. Location and all that may not be required for instance variables, but for loading player stats, for example, thats pretty specific so I understand what you mean to do so non of that gets lost.

I am not sure if the save can be localized or is defaulted to web data or not, but I do believe you are able to specify save and load locations. Looking into this now and will update if I find more that might help!

Variables (global or instance) are not very convenient for this purpose.

Dictionaries and arrays are much easier to work with, because you can export/import them with one action (as JSON).

So I'd recommend putting all data that needs to be saved into one or several dictionaries and export them as JSON to a text file.