How do I get started with creating my app?

How do I create an app that allows users to monitor their calorie and nutrient intake by taking pictures of their food, that would show the pros and cons of taking that food?

you can find some api to recognize the image, then look up in some table for calorie it contains.

search 'image recognition ' as first step.

How can I code it so that the chatbot will automatically know the information about the food just by someone typing in a food and taking a picture?

Where's the "image recognition?"