Is this considered healthy eating? (Read first please)

Hey everyone.

So I never really used to have healthy eating habits. I didn't eat much fast food, mostly cooked all my meals but I wasn't eating consciously. Like sometimes I wouldn't eat all day, and other days I would eat one heavy meal or just chips.

I recently decided I want to change my eating habits for a healthier lifestyle and I'll be seeing a nutritionist next week. But today I started my first day of eating healthy, I just want to ask if what I ate today is considered healthy for one day. I'm planning or incorporating other foods in the future of course. Just as a start is this good?

Breakfast: Greek yogurt with oats

Snack: 1 Tangerine

Lunch: grilled chicken sandwich with cheese, lettuce, tomatoes, and red onions

Snack: 6-8 cherries

Dinner: Greek salad with a little piece of leftover grilled chicken when I was grilling it for the sandwich.