(1) Validity of the lease.
you need to find out whether automatic renewal clause is valid in your state. In some state it requires written notifications at the time of renewal. In some state it might not be valid at all.
(1.1) If the renewal was invalid, they are month-by-month tenants, who only owe you 30 days notice, which they did on 1/2. They owe you rent 2/1-2/8 and late fees.
(1.2) If the renewal was valid They do not need to pay (800x3) immediately.
This is a situation of abandonment. They owe you rent until abandonment: 2/1-2/8, and late fees. Additionally you can seek DAMAGE from Abandonment, not RENT (since they already moved out).
Because you recover possession on 2/8, it is your responsibility to find new tenant to mitigate damage.
Damage from Abandonment is calculated from the date of the abandonment until (the date of new tenant moved in or lease expiration, whichever is earlier). As a landlord you have the duty to find new tenant to reduce the damage.
In short, their liability from the abandonment is UP TO (800x3), not immediately. You can seek recovery after 4/30, within your local statute of limitation, probably 1-2 years.
(3) Damage to the apartment
Depend on the state law, you may or may not deduct cleanup cost from security deposit by yourself. You might be required to refund deposit in full, but seek separate cleanup damage.