Hello there and welcome to the forum
If you're going to be letting your bunny out to run around a lot in a room then a cage like the one on amazon you linked to should be fine.
In my opinion the best thing to do is get the biggest cage you can fit in the space (Within budget of course), but of course everyone has different needs for different set ups.
For food, hay should be available all the time, a grass hay like timothy is perfect. When they're young (below six months) you can feed them alfalfa hay, or alfalfa based pellets, and then transition them to timothy hay and based pellets from 6 months of age. The pellets you buy should be high in fiber, and very low in calcium. Don't get food with all of the seed bits and corn etc in it as it's not really good for them. 1/2 a cup per day should be sufficient per day as already stated, although up until 6 months you can probably feed more or unlimited to help with the growing process.
In terms of feeding fresh greens etc. Some people don't do it, others say introduce early, and others say intoduce after six months. If you are going to feed greens, some good types are cos lettuce, cilantro, basil, parsley, rosemary, silverbeet. Things like carrots and apple should only be fed as a treat in tiny amounts (like the size of a fingernail) no more than once a day. With any of these fresh foods, you should always introduce them one at a time and very slowly as rabbits have sensitive tummies. Start off with a small piece the size of a fingernail and slowly increase it if all is well, then introduce the next one.
Also, don't forget that your rabbit will need lots of toys
Plastic baby keys, toilet roll tubes, old phone books, carboard boxes etc are all good fun for bunnies!
Also, the best rabbit friendly cleaner is white vinegar, I usually dilute it in a bit of hot water and then scrub away. Don't worry about asking so many questions, it's the best thing you can do!