Python RFID check in check out

I've been playing around with a keyboard emulated rfid reader with a plan to make a simple check in / checkout system.

Thus far I've managed to make a database using sqlite and can call it and display tables etc. But now I'm stuck and not sure what to look for or where to start.

My aim is to scan FOB once to display a name on a tkinter GUI then scan again to take it off.

Where would I begin with such task? I have tired a search but no luck.

Cheers

Shane