If you want to know exactly what you are eating the only way to do that is to make what you eat yourself. You can chose every ingredient, every spice, how much salt, and all the other details to make it delicious. Choosing what you want to eat is the start of cooking.
Cooking starts with recipes of course. There are an endless supply of them. You can start with your Mom’s recipes. Or go with Julia Childs, Martin Yan, or Michael Chiarello. Find a magazine that has pretty pictures. Cut out what looks good. And make it a few times. If you do not like a recipe you do not have to keep it. You never have to make it again.