Congratulations on completing the Transaction, the vehicle is now yours!
Now the fun begins, and so does the responsibility. Do these things immediately!
Follow these basic tips to prevent your car from falling into ill repair.
Check your oil monthly.
Check other fluids twice a year (power steering, engine coolant, transmission fluid)
Rotate tires every 5k-10k miles
Get it inspected [according to your local laws] and registered in time, even if you are not driving it for some reason.