I want to ask how do you count the calories for example of something with undefined calories like a soup or some new sort of home made sandwiches. Also I would like to know how can I calculate my calories limit ( 91kg, 176cm ).
When calories are not available from a label, you have to do the next best thing. Break down what's in the food and consult a nutrition guide. For example, for soup, if you knew the amount of chicken, veggies, etc. you can come up with a rough estimate of the caloric count. In order to estimate, you'll need to become proficient on serving sizes. Most nutrition guides will define calorie counts in terms of common serving sizes. As for calorie limits, that would depend upon what your goals are. For example, losing, gaining, or, maintaining weight. Again, the "limit" would be an estimation and not a hard number. It would need to be adjusted based on your activity level.