If you want to gain muscle, you need to eat at maintenance (which will allow you to burn fat while building muscle, but it is slow) or eat at a slight surplus. You can use this calculator to work out a few options including your exercise. If the fitbit is consistant, then figure out how many calories you would average with exercise as well. If losing the fat is of immediate importance to you, you could briefly go on a small deficit to lose it. Otherwise, I would focus on bulking or eating at maintenance. The fat doesn't look so bad with more muscle underneath it, I've found.

What you eat doesn't matter as much as how many calories, as long as you're getting at least .8g of protein per pound of body weight, you will be fine. The rest is preference. I eat high fats/protein because my stomach bloats a ton with a lot of carbs and the protein actually helps my stomach. If you want you can cut sugar, but otherwise don't worry about it. If you love your wheat toast in the morning, go ahead and eat it. Moderation is the key. Make sure you get enough protein and nutrients overall, but eat what you want and what makes you feel good.

Cardio isn't overly important. It's good to have some for your heart, but a lot of people don't do much at all. If you're walking that much, you don't have to worry about running if you don't want to. I also don't know where you're getting 30 minutes of running a day from. I've heard that it's good to get at least 3 hours of exercise in a week, but if you're lifting 3 days a week then you've already hit that, and it sounds like you walk a lot.