WHERE do I start!?

Ninkyou

Honestly, just plug all of your goals and info into MFP and eat the calorie goal it gives you plus exercise calories.

You can hit that calorie goal every day with whatever foods you choose. If you eat what you like, you're more likely to stick to it long-term, but aiming for a balanced diet is always good from a nutritional perspective.

Do whatever exercises you enjoy. Having a HRM will make it much easier to log accurate calorie burns.

Really, just keep it simple.

Calorie deficit for weight loss.
Exercise for fitness.
Log everything accurately and consistently.

It works.

All of this.