It takes around 1 hour to 1 hour and 20 minutes to cook a 2 lb meatloaf depending on how well done you like your meatloaf.
Usually cooking the meatloaf for 1 hour will be long enough to fully cook the 2 lb meatloaf but if it's not done to your liking then put the meatloaf back in the oven for another 15 minutes or so.
When cooking the meatloaf preheat the oven to 375 F and then put the meatloaf in the oven when you're ready and set a timer for around 1 hour and check on it.
Then if it still needs cooking put the meatloaf back in the oven for another 15 minutes minutes or so.
For me I've had meatloaf done at 1 hour though.
Another good way to tell when a meatloaf has cooked fully is to use a meat thermometer and when the meatloaf is fully cooked the meat thermometer should register 160 degrees F.