A notice to quit is the first step, not a court order to leave — you still have options. Paste it for a read on whether it's proper.
A notice to 'pay or quit' or 'cure or quit' gives you a short window to fix the issue (or move) before the landlord can file in court. It is not itself a court eviction.
Check it states a reason and a valid period for your area. You may be able to pay/cure within the window or contest it. Contact legal aid if unsure.
Not automatically — it's the start of the process. If you don't pay/cure or leave, the landlord must still go to court to evict. Verify the notice is proper first.