Hi,
As a type 2, you get to decide where you are happy running your blood glucose - within reason.
This chart may help.
The NHS suggests being below 7 before food, and no higher than 7.8 at 2 hours after food.
Personally, I have read some stuff (see the bloodsugar101 link in my signature) that makes me want to run lower than that. I am really not convinced that being that high won't cause long term complications, so I try to never go above 7 at any time. Don't always hit that, but it is a goal.
So really, it is best to test just before eating, and at 2 hours after. But you need to be fairly accurate with the timing, or you won't be able to make proper comparisons between different foods and meals.
When I started testing I did this
On waking
before and 2 hours after breafast
before and 2 hours after lunch
before and 2 hours after evening meal
before and 2 hours after any carby snacks
Sounds a lot, doesn't it?
But don't worry, if you test a food or meal several times, and you always get a fairly consistent result, then you can ease off on testing that. For that size portion.
You will learn very quickly that portion size is critical.
Nowadays, I only test my on waking bg (when I remember) and then strange or different food choices, to see the effect they have. I never test foods that I have confirmed are ok with me (like bacon and eggs for breakfast, or chicken and salad, or any old faithful like that).
Hope that helps.