Again, start first with your doctor's recommendation, but in the wake of my heart attack three years ago, the main thing I was advised was to keep saturated fats low, trans fats to an absolute minimum, and try to avoid foods high in sugar. (The latter can cause your insulin to go up and down, which can increase your triglycerides, that are closely related to your cholesterol.)
In terms of eating at WDW - I always talk to the chef at each restaurant and tell them straight out how I am eating. Sometimes they will suggest particular things on the menu, often they will offer to make something not on the menu. The latter have been some of the best dishes I've eaten at WDW.
Having said all this, I know of families who tend to have high cholesterol that don't have unusual health problems. The family just has something in their genetic makeup that gives them unusually high cholesterol, but with a body chemistry that somehow doesn't have problems with it.
ETA - if your doctor is not putting you on meds, that's a good sign. He/she thinks that your condition is mild enough that you can improve your situation without it. Cholesterol meds can cause liver and kidney problems in some folks, so it's best to avoid them if you can.
There are also tons of reputable places online with information about this. I would start at the Mayo Clinic web site and go from there.
I'll finish the way I started - listen to your doctor's suggestions, and then contact the WDW Special Diets department.
First off, if you can avoid anything white...go brown...brown rice instead of white, whole wheat instead of white..whole grain pasta instead of plain white pasta...try quinoa or barley..or oatmeal...these are high fiber foods which helps lower cholesterol...also, if you are in the mood for eggs, try scrambled egg whites, or an egg white omelet with vegetables...but ask them to go light on the oil...many people forget about that. If you are in the mood for something sweet, go with fruit whenever possible...it may kill the craving for the sweetness. For meats, try a high protein, low(er) fat meat like chicken breast...or filet mignon, or if you are adventurous...buffalo. Sometimes, however, you will get a craving that you just can't get rid of...in that case it's better to splurge and do a small portion of what you are craving...and then make up for it later in the day...If you know you are going to have eggs benedict for breakfast, then plan on eating better the rest of the day...It's all give and take. You didn't get high cholesterol in one day, and you certainly aren't going to get rid of it in one day 
. I drink green tea with 1.5tsp sugar and a little milk or a decaf coffee with the same. I love to eat crackers with cheese and my favorite go to fruits are grapes, and apples. Like to eat trail mix with nuts and chocolate chips in it. Potato chips are a fav as is popcorn. Probably not a good idea to get tested right after the Holidays when I was eating lots of sugar snacks. I am also addicted to chocolate!!!!! We don't eat too much ground beef or steaks. I try to cook with ground turkey and turkey sausage. Always choose chicken breast over dark meat. My mother was on pills and my grandfather was too. Probably something I inherited 
Just feel kind of young for it (almost 40).
