Hi Rick.
Welcome to the forum. Have a good look around and when you are ready ask any questions.
As for the 'confirmation test' it is probably going to be a GTT (Glucose Tolerance Test) as you have already had a blood test.
You should have been told to fast overnight, then they will take blood out of your arm, you then drink a measured amount of glucose. You then have to wait two hours and they then take another sample of blood from your arm. these are then sent away for analysis
If you haven't been told to fast, then it might just be another blood test. They have to confirm the initial diagnosis.
Nothing to worry about either way.