Wrap it up in your own object (or interface) and pick one of the above and try it.
If you consistently only use that one object everywhere, then if you want to change the internal storage structure in the future, you just rewrite that one object.
Work through some JSON tutorials, it will almost instantly become obvious what is going on. It’s hard to get any simpler than JSON data, plus you can edit it with a text editor to find bugs while you’re developing.
Are you just looking for a savegame system? Because that’s not traditionally called a “database.” There are tons of tutorials for those, but here’s my own scribblings:
Load/Save steps: