The first, most basic, and most urgent step is to get rid of chemically modified foods that have permeated our diet. These are unnatural ingredients that our bodies do not recognize or process as food, especially in the large quantities in which we have come to consume them. Specifically this means eating no hydrogenated oils, nothing high fructose, and no MSG, but the basic idea is to quit eating food with ingredients on the label you don't recognize and foods preserved with high amounts of sodium. Kristen at Food Renegade says you should ask yourself whether this food is something your great grandmother would recognize.
Healthy Natural Fats
This is related to the previous point, but worth expanding on. Any type of vegetable based oil is a modified food. It is a Polyunsaturated fat which your body does not recognize or know how to digest, so it just stores it as fat. Stick to butter, ghee, olive oil and other saturated or mono-unsaturated fats. More on why butter is okay later. But just trust me and quit eating fake fats.