Hi, Elizabeth! Hoop-Dee-Doo! You're going to have more fun than a pig in mud! According to the Walt Disney World website, "Guests may pick up Dinner Show tickets up to 7 days prior to show date at any
Walt Disney World® Resort Guest Services Desk. Please arrive at least 30 minutes prior to show time. If you chose to pick up your tickets at the show box office, please arrive 40 minutes prior to show time."
Now, for my humble opinion, I believe you should pick up your tickets at the Resort Guest Services as soon as you are eligible to do so. We did this on our last trip and were fortunate enough to get a front and center, stage-side table. We became part of the show! However, even if you are unable to pick up your tickets until right before the show,
ALL the category one seating is wonderful! I've never requested a specific spot because the players do a great job getting everyone involved. Be assured that your category one seating will have you in the middle of the fun.
The other meals you asked about are character experiences. Where you sit for those is irrelevant as each character circulates to each table to give Guests some one-on-one time with them. Happy planning and have a Magical vacation!