The Newton is great for jotting down notes, and the notes app (though they don't feel quite like the apps we're used to) is the main page. From here you can access mail (InOut), contacts (Names), a calendar (Dates), and a few useful features like Find and Assist. More apps are found in the Extras drawer. You can also get an onscreen keyboard by tapping the mini-keyboard icon.
For fun you can turn on the backlight, but it's not really necessary in the emulator. On the real thing it's very useful.
Here are the Extras that come with it. You can find other software packages to install and they'll show up here. You can also organize the icons (notice how these are "Unfiled") by tapping and holding to select one, then tap the folder icon to file it somewhere. This same method is used for notes, contacts, calendar events, etc.
Installing a new package is easy, just find one (check out the Resources page) and click Install Package, then select your pkg file and it's done.
To see how the soups work and connect with each other, go to Dates, tap New, then tap Meeting. Give it a title and then tap Invitees. There are some entries in the contacts already so you can pick a few to add to the meeting. Tap the X when you're done, it'll keep what you've selected and close that part.
Now tap Location to add a location. Again you can pick from your Names, let's meet at Alice's Restaurant.
This seems pretty simple to us in 2019, but in 1993 this was new - most programs did not interact this nicely. Something as easy as choosing items from your contacts program in a calendar program was not a streamlined process.
There's also a button down at the bottom called Assist. Tap that and something like an early Siri will help you with whatever you need. Tap please and select the type of request you want. Tap Do and then you can add details to the request. You can also highlight some text (tap and hold, then drag the thicker pen to select) and then tap Assist.
Try it out, write "call Bob" in a note, then highlight it and tap Assist. The assistant will bring up the phone dialog with all of the details for Bob Anderson already filled in.