Answering in order:
Yes, you can decide the content of a dream beforehand, and it’s called dream incubation: you can look it up on Google, or read this Erin Pavlina article.
There’s chocolate, bananas, milk, pop corn, and a series of other fruits and vegetables that I remember of.
Yes, meditation can be very helpful, as it helps you being aware in general, you can do it in bed to induce a LD 
(look MIWILD) and white noise can help you detach from the waking sensory experience, allowing for a smoother transition into dreams and dream senses.