This is why Spark doesn't actually let you track "sugar".
Many products simply don't label the sugars, and of course some naturally occurring sugars are good for you.
A good goal is 0.00 "added sugar". None. Cottage cheese will have naturally occurring lactose sugar from the milk so you would tell by reading the ingredients. If "sugar" is listed as an ingredient (or any of its many other names) then it has added sugars in it.
Don't try to aim for any particular amount of "sugar". That isn't the path to health. Just eat a healthy balanced diet, mostly free from candies, sweets, baked goods, and anything with "sugar" in the ingredients list, especially if it's high up.
Deb, in New Zealand