This will differ from person to person. In general and everything else being equal, someone whose daily routine requires a lot of physical effort will need more calories than someone who sits at a desk all day. Since I don’t know what your life is like, I can’t give you even a ballpark figure for your calorie intake needs. You should not reduce your calorie intake so much that you cannot function to fulfill whatever responsibilities you have.
Perhaps my rule of thumb would be useful for you: I take my usual meatless evening meal and reduce it by 25%. That’s the size of my Ash Wednesday dinner. Now take the size of that dinner, reduce it by 25% then cut what remains in half. Those are my breakfast and lunch meal sizes. The main meal is smaller than my usual dinner, and the collations don’t add up to the main meal.