Food is one of the essentials of our existence, providing the energy we need to create and grow.
As an essential everyday skill, and a form of art culminating from centuries if not millenia of our ancestors' relationship with the land, cooking is a chain in the link that is being lost. With globalisation, fast food megacorps and New-Age diets, traditional cooking methods that ties us to our land and people, and allows us significant self sufficiency is becoming an increasingly threatened way of life.
With poor nutrition and knowledge, a significant percentage of the population has been quite literally reshaped into overweight, unsightly caricatures of humans, barely resembling the men from which they descend whom built the very nations in which they reside. In many places where such food becomes a viable alternative to home-cooked food, it is unbelievably easy to indulge especially for those with no cooking knowledge, and so these people end up in detrimental physical states.

For those unfamilliar with cooking, I suggest recipe boxes, in which self chosen recipes and all ingredients are conveniently delivered to you, as a good way to grease the groove and make it easier and something fun to get involved with.
With the internet, access to virtually all types of recipe are accessible.
Spend time with parents, grandparents if you can, to learn more about their cooking traditions, for it is your role to preserve them.
Cooking is a social event, invite friends over, family, etc. and make/share food together. Make a cheap and rewarding event out of it.

In terms of diet, I would suggest calorie counting to control your weight, eating at a surplus or deficit where necessary for the purpose of weight manipulation. There are a plethora of good quality apps available for tracking food intake. Even if healthy, it is a good idea to do this for a few weeks as a method of portion control, and a way to grasp your macronutrient intake.
Whole foods, and traditional recipes tend to be the most balanced foods - they are time-tested after all.

As with all types of self improvement, you must gradually ease your way into the new way of life, not overcomplicating the process. For example, not trying some organic, non GMO, vegan diet when you are unable to cook or diet in the first place.

As you progress, consider growing your own food. You would be surprised with how well you can supplement your diet with only a small piece of land, and taking a bare/overgrown piece of land, and using it to create something edible and delicious is an extremely rewarding experience.