Eating cheap

I always tell myself that I am going to try to eat healthier and that I need to start trying organic foods or foods that are just good for me in general! I only eat fast food on occasion but even when I don't eat fast food I tend to put a lot of salt on my food or the food I cook isn't healthy ether.  The only time I eat healthy is when I am at my parents house.  The only reason that happens is because my dad cooks and because they have the money to buy those healthy foods.  I could ask them for money to buy the extra healthy foods but I would prefer to keep it cheap and save my money for other necessities instead of depend on my parents too much.  The other problem I have with eating healthy is that I don't know exactly what is healthy.  Some times I wish there was a clear cut way. I wish I was educated better on how I should construct my diet and healthier approaches instead of having to dig to find diets.  I am actually in good shape and rather healthy but I know for a fact I could do better and costs & lack of knowledge is a big problem for me in that aspect.