I am trying to lose weight. At first I was just told to exercise and decrease calorie intake WHICH I DID..Now I'm being told that if I don't cut out junk food like sunchips, subs, hot dogs, fries and etc..I won't see results at all..So I was thinking if I just ate a lot of fruit mainly grapes and bananas along with a sub would that be a start ?
Should I just try a fruit diet ?

It sounds like you're doing fine. Losing weight is a slow process and you can get easily discouraged. Keep it up. You will see results and you'll feel better too. Do cut down on the junk food though. If you are going to have some though, once a week and as a reward for a good training session (weight training perhaps). And maximize good foods. So if it's hot dogs you like, buy whole wheat buns, turkey dogs and use mustard and veg to fill (tomato and cucumber as an example). If you keep that kind of habit up, you'll eventually wonder how you ever ate regular hot dogs in the first place.
(Fruit is good! Good! Good! Good! And vegetables!!!)