Hi Crimson. I'm speaking as a type 1 here but hopefully I can still give you some relevant info. First off, if you don't have a blood testing meter, I would say getting one is very important. I know T2s sometimes struggle with their health team prescribing test strips, but really push this with them. There is no 'one dose of insulin fits all,' so testing is the only way to know you are giving yourself the correct amount. I tend to test before, and two hours after a meal.
There are plenty of meters to choose from. I have not used the Aviva myself, but have used Accuchek meters in the past and have been satisfied with them. Other brands include OneTouch and Bayer. The meters are only half of the equation. Noting down what you ate, how much insulin you took, and how this affected your blood sugars will give you a good picture of how much insulin you need.
If you are injecting basal/bolus you will likely be having more injections each day than previously. Try to get into good injecting habits early on. Change your needle after each injection, and constantly vary where you inject. Using the same injection site all the time causes problems with the insulin being absorbed there properly, and can make blood sugars unpredictable.
You probably already do this one, but just in case, always have a source of glucose with you. My preference is dextrose tablets. They are convenient to carry around, and raise blood sugars rapidly in the event of a hypo.
Hope that helps, and best of luck.