I'm a 22 year old female, 5"5 in height and weigh 148.8 pounds. what's the safest amount of calories i should eat to lose weight and not get sick?

Depends on activity: For a woman your size who is fairly inactive, a 1800 K diet should allow you to lose a 1#/week, or 1300 for 2#/week, which is the fastest recommended. If you are more active, you may be able to eat more and still lose. See https://www.calculator.net/calorie-calculator.html for a calculator that estimates calorie needs and weight loss and how exercise affects this.