Here you can see 2 ways to hit 1800 calories. 1800 calories is a good amount of calories to fuel high-energy workouts, stay focused throughout the workday, and sustain slow yet steady weight loss.
I personally recommend a 1800 calorie diet for women who are about 5'3-5'7, and weight about 120-160 pounds. However, this can change based on your dieting history, metabolic rate, activity rate, and more. 1800 calories is ideal for those who struggle with over eating, because it provides the body with a good amount of nutrients, while keeping the body in a small caloric deficit to support weight loss goals. Most people will lose weight on 1800 calories. If you are looking to maintain, you will likely need more.
I always recommend centering your diet around vegetables, fruit, and protein, then adding in complex carbs and healthy fats to finish up your calorie needs.
As you can see, it doesn't really matter if you're eating traditionally "clean" or "unhealthy" foods...at the end of the day, calories matter much more. When it comes to weight loss, many studies show that regardless of high-carb, low-carb, keto, high-protein, etc, so long as there is a caloric deficit present, weight loss is consistent and evident.
What should guide your diet decisions though, is what can you stick to long term? What is something you can see yourself following for at least 3 months? Many people think of dieting as a "21 day fix", when in reality it takes a while to see lasting results.