Can I save a folder with datastore?

Yes....... per say.............

You cannot take an entire folder and save the contents of it in a traditional sense of grabbing the folder and calling the datastore save.

You can however convert the contents of your folder into a table of sorts and save that.

It might look something like saving the names of folder objects as the key, and the values of the folder objects as the values. Essentially creating a dictionary.

Check this out for some help with tables and what I mean with keys and values. https://developer.roblox.com/en-us/articles/Table