So, you have one day in the park? Are you arriving before opening? And staying until the park closes? Or will you be spending only part of the day there?
I would buy tickets in advance, but it doesn't really help as most locals seem to buy their tickets online so it takes a LONG time for them to process their tickets at the gates.
It will ultimately depend upon when you go, what other Disney parks you have been to, what is most attractive to you as guests, etc, but I would roughly prioritise a visit as follows: run (and I do mean run) for Fast Passes for Soaring. If you don't get a FP, then be prepared for a LONG wait in the Standby line. Then hop into the standby line for Roaring Rapids (don't forget to bring your rain ponchos). Then head around to Pirates of the Caribbean. It will probably then be time to grab another Fast Pass, so head to Tomorrowland and grab a FP for Tron and ride Buzz Lightyear while you're there.
That will cover the biggest / best attractions (in my view). You could then consider doing Crystal Grotto, Peter Pan, Seven Dwarves Mine Ride, etc if they appeal to you (and if the lines are short enough). I would try to do Pirates and Tron at least twice. In particular, I would try to ride Tron again once it is dark.
I found Camp Discovery to be a lot of fun, but the line was long and it was easy to get caught in bottle-necks as some of the guests seemed to have trouble navigating the harness attachments and the course options.
Tarzan was really good. I would skip the Frozen and Captain Jack Sparrow shows as I thought they were both pretty average.
As for food, we only really enjoyed the Tangled Tree Tavern. The food everywhere else we ate, including Tribal Table, Wandering Moon Teahouse and Barbossa's Bounty, was very average - entirely flavourless and often the meat came on the bone. Eating in Barbossa's Bounty is nice for the atmosphere since it's set up like Blue Bayou, but doesn't charge Blue Bayou prices. There are a number of good food options in Downtown Disney, although the lines for the restaurants can be VERY long around lunch and dinner times as it seems a number of guests leave the park to eat. If you want to make the most out of your time, you probably don't want to leave the park for food.
Have fun!