Translation:
1. Eat the same thing for 2 weeks and if your weight stays the same - you've found your maintenance calories.
2. Drop 10-20% or 200-400 calories off that amount, then hold that until your weight stalls/you aren't seeing changes in the mirror, then rinse and repeat.
3. Of those calories, as a bare minimum:
- keep your protein intake up, particularly as you are cutting (opinions vary but you can't go wrong with about 2.2 grams of protein per kg, eg at 81kg, I eat roughly 180g protein a day)
- have a decent amount of fats, (opinions vary but you could start with about 1 gram of fat per kg, eg at 81kg I eat roughly 80g fat a day - if that's too much, go lower than this amount)
- fill the rest of your calories with either more protein, fat, or carbs.
4. Keep up your weights 3x or so a week.
5. At least initially consider using an app such as dailyburn or myfitnesspal to track your calories.
Otherwise, do what works for you eg some people need more or less carbs.
Enjoy.