It would help if you showed us what does not work. The game saving part is pretty well documented.
Countless tuts on YT, too. Perhaps get it to work with a simple variable first, in order to get the system running, and only then extend to envelop the tutorial saving progress. It’s impossible to advise without knowing how you measure tutorial progress. It might be a matter of saving that 1 int variable, and you’re done. As in: