Well, go and get a textbook on nutrition that is used by graduate students in this subject at university. That is your source of information.
The three sources of fuel in the body are fats, sugars and starches, and proteins. Since protein is expensive and has to be broken down in the liver then it is best to get energy from fats, starches and sugars. It should be easy to find these foods if you look. One useful way is to buy the little Calorie Counter book that cost about $5. Then study which foods have lots of calories and consume those. Make sure you have a balanced diet. By balanced I refer to getting all the essential nutrients from different food groups. Bodybuilders tend to go to extremes when it comes to diet. Most have little clue about what they really need but consume way too much of just about everything. That is crazy. Consume the minimum that you need. That is being intelligent. However, you will have to study nutrition first. If you have to ask basic questions then you really need to learn more. Then you will be able to assess information much better. By the way, there is no such thing as junk food but you can have a junk diet. A food cannot also be junk.