When you say "downloaded", what exactly did you download? The single file version? It will be wherever your download folder is.
By itself, the single file version is just a very elaborate web page. It can't save itself or your changes. For that, you need one of the 20+ saver solutions. You can save to a dropbox folder using one of the saver solutions. If you're on a PC, and using a chromium based browser (most browsers are), or Firefox, then Timimi is a good choice. You install an extension. You install a local save file. You configure your browser a tiny bit. And then you're good to go.
You can create hierarchies of tags and view them easily using a macro:
<<toc "Contents">>
(where "Contents" is your root tag. There's a whole slew of
TOC macros that can give you different views of your data.
You can roll your own table using the listwidget, but you might find it easier to install the shiraz plugin and use
HTH