Oh Nora don't feel bad! Lots of people don't know what to eat when they first start a weight loss plan. I'm going to direct you more toward low carbs and whole grains. This will help you feel full longer. I think your sister was right about the noodles because they are made with white flour (simple carb) and will actually make you feel hungrier.
For breakfast eat eggs: fried, scrambled, boiled. You can even add a little bacon. If you have to have bread make it only 1 slice of a hearty whole grain bread.
Lunch and dinner have some protein about the size of the palm of your hand. This can be like a chicken breast or even the hot dogs you mentioned. A good serving of vegetables like green beans or broccoli or cauliflower. Maybe not corn.
There are snacks like sugar free pudding that are real good. You may want to avoid fruit at first. You can add some later.
Stay away from white stuff like white bread, noodles, rice, cereal, anything made with sugar, etc. Find sugar-free stuff and make sure the carb content is pretty low (like under 10).
If you find it hard to stick to your plan I always recommend something like R&D Diet Cookies. You eat them during the day (they are filling and satisfying) and you eat a dinner like the ones I mentioned above. The cookies keep hunger and cravings away so it is easier to stay committed to a diet.