I recommend that you take a nutrition class. Hospitals usually have such classes available. Once you understand proteins and carbs eating a high protein/low carb diet will fall in place.
One mother suggested having your veggies as carbs. Not all veggies are low in carbs. You'll want to choose those low in carbs for the majority of your veggies.
Not all protein is equal, either. You do need good fats but fewer animal fats.
A good way to start is to avoid white foods such as potatoes, white rice, white bread and bakery products. Not all bread is equal either. Just because the wrapper says it's whole wheat doesn't mean its healthy. Look at the amount of fiber it contains. The more fiber a food contains the more calories it takes your body to process the bread which results in less calories overall. You also need fiber to keep your digestive system working efficiently which will help in losing weight.
Nutrition is complex but not difficult once you learn the basics. You can do it!