For the first year just worry about your protein and water intake. The new way of eating how to combine things etc. is a lot to grasp right now, you don't want o get overwhelmed.

Now at 3 years out I am still tweeking things here and there. I do a 40% protein, 35% carbs, 25% fat. ratio. I also eat 2000 cal a day. I do spin class 4x a week and weights 5-6 days a week for an hour at a time.

A lot different than my previous life. No exercise, very sedentary, walked the dog one a week, ate 3 full meals, probably 3000-4000 calories a day. Not good.

My nutritionalist says not to bother with how many carbs, protein, calories etc. But to have 3 small meals a day with no snacking so that's what I have been (trying) to do and have lost 80lb in 5 months.

first off ask your doctor/ nutritionist because different people need different amounts. second I think they dont tell you the exact needs a first because its hard to get it in right after surgery and many people start freaking out and so they want you to focus on the protein more then the calories and as you get further out and can eat more of a solid/ normalized diet then you need to really start watching your calories. but the rule of thumb I was told and I experienced:
generally 300-600 the first month (since you cant eat much)
generally 800-1000 months 2-3
1000+ months 3+ (depending on exercise and needs)
between 1200-2000 when you hit goal (again depending on height and exercise)

as for fat and carbs I wasnt given exact number which annoyed me (lol) I was just told to use commonsense. but also your own sensitivities may set the tone for that - for example I am a little sensitive to fat so I tend to have lower fats then what is recommended most days, but since I LOVE carbs I must limit my intake (goal is set to 60, but I try not to go over 100), and my sugars (rarely a problem also, unless I eat sweets) so I set it on MFP recommendation.