I'm definitely not a YC expert, but I'll give you a few things I learned while I was there last month (and hopefully real experts will chime in!)
1- Fit in pool time, because Stormalong Bay is irresistible to pretty much everyone, especially 8-year-olds. It's easy to lose track of a kid in there, though, so if he's not a strong swimmer, keep an eye on him. (There are lifeguards, of course, but still.)
2- Unless you already know and love the food at Beaches & Cream, it's not a must-do. Have dessert there, definitely, but don't make a meal a priority, not with so many excellent lunch/dinner options nearby.
3- If you like coffee/tea in the morning, you'll be happy that the Ale & Compass lounge in the lobby is open at 6:30 a.m. They've got pastries and cereal too. I loved getting my coffee every morning and taking it to the back deck and enjoying the beauty and peace and quiet of the resort. The views are just excellent. If you want something more substantial, the Beach Club Marketplace is a short walk away and they open around 7 a.m.
You've also got a wealth of quick service options on the Boardwalk, including the excellent Boardwalk Bakery. It took me maybe 7 minutes to get there, and the walk is really pleasant.
4- I don't know what room category you've booked, but try to ask for a room close to the lobby (floor doesn't matter). YC is sprawling and the inner hallways are looooooong if you're placed at the far end of the resort. It's easier to take advantage of the pool and restaurants and feel like "part of the action" if your room is near the lobby.
5- I'm sure this can happen at any resort, but I had pretty bad luck last month with some Magicband charges being doubled. Every day, ask at the front desk for a copy of your room charges, and if you find any, the CMs will quickly and happily remove them. Just a heads up.
I hope you get more tips, because I'd love to read them too! My stay at YC last month was wonderful in every way, and I can't wait to get back there. You'll love it!