How many calories does a man need per day if he’s looking to lose weight ?

Superfoods for building muscle mass https://whatsteroids.com/

If he's not consuming carbs or very low carbs, then why count calories at all? There's no sense in counting calories anyway.  20 grams of carbs or less a day is a great way to weight loss.... and no processed foods, no refined oils or fats (just natural fats such as olive oil, avocado oil, coconut oil, lard, butter, and fats which are present in meats)

Depends on your age, height, current weight, goal weight, and activity level.

A BMR calculator will tell you the minimum number of calories your body uses.  A TDEE calculator allow you to mix in your activity level.

You calorie consumption needs to be 500 calories or more under your calorie usage every day to lose a pound of fat a week.  

An easy option is to calculate the BMR of your goal weight.  Use that as your calorie limit each day.  This will ensure you are currently in a calorie deficit and will help train you to eat the right amount when you reach your goal.

Depends on your height/weight and activity levels.

Stick your details into https://tdeecalculator.net/ to get a rough starting point.  Pick something sensible and adjust after a few weeks depending on how you get on.  As you lose weight you will likely need to lower it further.