If you can't track what you're eating you're going to either experience slower results or risk completely halting any progress at all.
Each gym plan inside the app has your personalized macros giving you the exact grams or protein, fats and carbs you need. The next steps would be for you to start to learn the best food combinations to match them. MyFitnessPal is a great app for this but the principles remain the same with other food tracking systems.
You scan or search for foods that you eat and learn what’s going to work for your macros. There’s endless information online about what foods are good for you, so we’ll not cover that here. What’s important right now is monitoring the grams of protein, fats and carbs you eat.
Change won’t happen overnight!
Generally, within two weeks if you're tired of scanning and tracking everything you consume you'll be able to eyeball your portion sizes pretty close. Just like a solid training plan though, you’ll get better results putting the work in!