Quick disclaimer - I don’t count calories and never did throughout my weight loss/maintenance IF journey. I counted for three weeks last month to review protein consumption for muscle gain, but dropped that pretty quickly once I felt comfortable with where my protein sources were coming from and how much of it I consumed.
I think it’s important to listen to your own satiety/hunger signals. Every day won’t be exactly the same. Some days you’re going to want 1,900 calories worth of food and some days you might only want/need 1,600. Pay attention to what you’re consuming. How does what you ate yesterday make you feel in the present?
As an IF beginner, I recommend you just fall into rhythm of your new lifestyle. Develop the habit of fasting and tweak it until it’s an easy lifestyle for you to live long-term.