Unfortunately this is where you need to know a bit about the composition of food, and biochemistry.
All yogurts will contain some sugar in the form of lactose, which is the sugar that occurs naturally in milk.
If the yogurt has fruit in it, it will also contain some sugar as fructose, which is the sugar that occurs naturally in fruit
Read the label carefully, both the composition and the ingredients list. If there is sugar listed in the composition only then this is naturally occurring sugar and you can't escape it
If it is listed in the ingredients list as well, some of it will be added sugar, usually as sucrose. This sucrose is the sugar that occurs naturally in sugar cane or sugar beet, and it is extracted to produce the table sugar or 'sugar' that we all know. It is added to the yogurt to make it taste nicer, ie sweeter, and as a filler
You should try to avoid yogurts with added sugar,but remember that you don't have to live off the stuff entirely, so perhaps an occasional amount is OK as long as you are aware of it and allow for it
The latest thinking seems to be that naturally occurring sugars and fats aren't too bad, again as long as you are aware of them
According to 'Reverse Your Diabetes' Greek yogurt is probably the best choice, even if it is full fat, as long as it doesn't contain added sugar
Something you could do is to make your own yogurts by getting natural yogurt, either full fat or from skimmed milk, and add your own sliced/chopped fruit. It won't be as sweet, but just as you get used to tea & coffee without sugar when you develop diabetes, so you get used to that kind of yogurt
You can also make savoury yogurts by adding chopped veg; raw or cooked
I see you have a 'salady lunch' Sometimes I just pour natural yogurt over my salad and stir it all up, as a dressing; a bit like cottage cheese, but runnier. then I eat the fruit on its own