Hi there Carin and welcome
If you open the printer up where you put the ink cartridges into, do you see any paper there at all? It can be a very small piece, just enough to set off the sensor.
Please let me know.
ok, Can you please remove the power to the printer (so unplug it from the power socket).
Then wait 10 minutes, connect the power again to the printer, turn it on and tell me please if it is now operating correctly.
Let me know the results please
ok, use a vacuum cleaner and with it powered off, vacuum the inside of it out to try to remove anything that could possibly be caught, do this from all openings