You will quickly realise it is not as easy as it sounds when in practice things can be very individual and variable. For example the amount of carbs in a meal can have a different outcome depending on lots of different factors, time of day, what you eat them with, what the carbs are, some people tolerate bread but not rice or pasta whereas for others it will be the other way round.
If you look at precise numbers and a single test of a food then it can become disheartening and it is better to look for trends.
Don't be in too much of a rush to bring your blood glucose levels down as it can be kinder on your body to do it more gradually to avoid issues with your eyes and nerves.
Just take one day at a time and have a plan of action.