I'd start with 12 calories/lb of bodyweight and adjust as you actually get leaner and the scale goes down, e.g., a weekly weigh in. If that doesn't yield effective results after a few weeks, adjust down to 10 or 11 calories/lb of bodyweight. You can certainly use LBM too, I've seen people do both, but if you use LBM I'd go with 12 calories/lb at minimum.
The number of meals per day, i.e., meal frequency, probably doesn't matter as long as you are satiated and reaching your goals. Focus on whole, minimally processed foods, e.g., fresh fruits and veggies, whole grains, dairy (if you can tolerate it), eggs and minimally processed meats. You don't have to eat just chicken and broccoli. You can have beef, seafood, turkey and pork, along with rice, sweet potatoes, and whatever other fruits or veggies may suit your palate.
From the last link I posted:
"Here's the simple game plan:
Animal proteins for essential amino acids and essential fatty acids.
Plants for fiber and micro's.
Whole food fats as the primary energy nutrient for sedentary, insulin resistant, obese populations.
A select few carbs (root vegetables and rice) as the primary energy nutrient for anaerobic exercisers.
And of course, "High quality H20" from the great water boy, Bobby Boucher."
I think oats are fine for breakfast. You'll get different opinions on here regarding consumption of grain-based carbs for weight loss. A lot of people find that they can eat grain-based carbs, as they can any other carb or macro, and still lose fat as long as you are in an overall calorie deficit and getting 80-90% of your calories from whole, minimally processed food sources, and I tend to agree with that based on personal experience.