Is there a good tutorial or guide on making multiple save files?

First let me say, I am still new to unity and learning C#. I recently learned how to save/load files (custom binary files). I can save and load no problem.

But now I would like to make multiple save files to display a list of 4 or 5 saves to select from. I could be wrong but I feel like this is a common thing in alot of RPG style games (and many other types), and has been for a long time.

However I am having a difficult time finding good info on how to do this. so does anyone know a good tutorial/site/video for doing or any info to point me in the right direction?

Say you have a UI showing buttons Save Slot 1, Slot 2, Slot 3, etc.

When a button is pressed it could call your SaveGame(string _theSlot) method and it would pass in “01”, “02”, “03” etc which you could use to change your current filename to filename+_theSlot