Now let me state some foods that are better to eat and what to avoid.
Except the apocalypse is coming, it's best to stay away from anything boxed, canned, containered or jarred. That means its been thru the processing mill. But there are things you can still get at your supermarket reasonably healthy without blowing your budget.
I generally avoid most diaries, but if you must drink anything make it whole milk, not skim. Get plain yogurt is OK and flavor/sweeten it yourself instead of their corn-sweetener or artificial stuff. Butter is OK. Lots of that especially for hot vegetables is good. Skip the heart-disease producing margarine. Margarine has to be the most processed food on this planet. If you knew what it looked like while they made it, you would not think of eating that axle grease, er, I mean margarine.
Meats are OK, the more grass-fed the better (or better quality cuts) as this may be expensive one may not eat as many as what one likes, however, in that case,
eggs, eggs and more eggs. My wife and I go thru 3-4 dozen a week, cheap protein.
Nuts are good, too, but "unoiled' A lot of them have cottonseed oils and other vegetable oils in them. Processed vegetable oils are very bad for you (polyunsaturated fats). The exception is extra virgin olive oil.
So as one can see, so far I concentrated on proteins, saturated fats and monounsaturated fats, the better kind for you.
For the non-meat and animal product end, lots of raw vegetables. Lots of salads. For that I'll give you permission to add some dressing on just to show I'm not a self-righteous kill-joy (I mean, heaven forbid if we should put a little dressing on our salads and make them taste good)

You can make your own olive-oil dressing with spices, too. In the summer, do as we do and grow a garden if you have the space. Actually, I look forward to eating salads and I don't understand why people don't like them. As I always joke, you can make it taste like the whopper burger vegetables without the meat. Nobody seems to complain about the small salad on their burgers.
To a lesser degree, eat fruit but not excessively. Berries of various type are good, as are low-sugar fruits. Bananas and pears are examples of some that one needs in moderation as that's too much sugar.
And along that line, CUT THE STARCHES. Most of what people eat are in this category. That includes (but not limited to breads, noodles, spaghetti, pizzas, cereals, and so-called "grain" category). If you have to have bread, get Ezekiel bread (or cereal). I guarantee you one slice will fill you up. This won't spike the blood sugar as badly. I can say oatmeal is also good, but I generally dislike "bland is grand" mentality like the medical establishment pushes. Oatmeal does not do anything for me.
I think I covered all the food groups. These are some healthy eating tips on your way to better nutrition.