I'd check out the library, if I were you. There should be some books on programming there, even for beginner levels. I think those should help you.

As for the app, you can enter fifty names at a time. Though, of course, a name disappears if a person does arrive, giving you more space.

What the CereVice does the moment somebody arrives is registers a person's real full name. You don't have to enter their full name on the filter. Say you want to enter "Leonardo da Vinci" on the filter, you can just type "da Vinci" or "Leonardo", and it will still work.

But if there's another Leonardo or "da Vinci" who comes in here, then you'll get alerted of their arrival, too.