When a landlord sends a tenant a 3 day notice to vacate or pay rent owed then you have 3 days to pay the rent owed or move out.
Then the landlord can take you to court to force you to move out if you don't move out on your own.
You can just either pay the rent owed within the 3 days or move out within the 3 days without needing to go to court to be evicted.
But if the landlord wants to force you out of the place then they have to take you to court to actually evict you from the place.
Being evicted in 3 days is highly unlikely because it can take a few weeks to even months to actually get evicted by the court.
However if the court orders you to vacate the property within a certain time on a certain date you need to move out otherwise a police officer will show up to force you out of the place and allow the landlord to change the locks.
If you fail to vacate the property when the police show up then they can arrest you to force you out.
If you can't pay the rent or the landlord has reason to evict you the best thing to do is pack up your things and move out without getting evicted through court.
Being evicted through court can show up on your rental history and records and make it harder for you to rent other places.