For Monday, you have two choices. In either case, the App Inventor chapter on databases is probably good reading.
You could walk through the Make Quiz/Take Quiz tutorial, which makes use of databases.
Or, you could develop a small app that provides an example of how you might use a database. Perhaps you could make your own personal phone dialer, for rapidly contacting friends. Or, a texter, that sends a pre-defined message to a pre-defined group of people. Who knows? You might come up with something else.
It doesn’t have to big and complex… just something that clearly illustrates how to create a TinyDB, add content, and get it back out.