Food companies try every trick to make carb counting difficult. Companies will tout "zero sugar" in the label even though the first ingredient is maltodextrin or maltitol or some other thing that quickly turns into sugar the moment you ingest it. The only way to get good at it is to wear a CGM and then see how your body reacts to things and then keep a mental list after that. A company may claim some product only has 2 net carbs, but I've found those claims to be false a lot of the time, with bigger companies being the biggest offenders.