I am about to do my 3rd solo trip on Monday, staying until Friday. I don't want to rehash what everyone else says, but wanted to add a few tidbits about dining alone. My first solo trip, I felt like an a$$ eating alone, and bringing a book or magazine to eat at Disney just seemed odd, but have found a few ways I can dine alone and still have a great experience.
Depending on the restaurant, ask if they have an extra space at the chef's table (i.e. Flying Fish). If they happen to have an open seat, you can eat there, talk to the chef and other staff without it being awkward.
Depending on location, eat at the Bar or counter - Tune in Lounge (50s Prime Time Cafe menu). Sanaa, Jiko, Kimonos (plus, they have karaoke), and the Cuban place at Disney Springs (forgot the name) to name a few.
Sci-Fi Diner is a perfect place for a solo diner. I have done lunch there twice solo and had a blast in my very own car lol. Plus everyone is looking at the same tired movie, so they aren't paying attention to you.
Dine with an Imagineer!! I am doing that for the first time this week.
Meet new friends on Disboards or at the park to share a meal!! I can't tell you how many times I have met someone on line for a ride, or at the resort pool, or here on Disboards and we just meet up to have a great meal at our favorite sit-down restaurant! I am an introvert mostly, but love meeting new people and it's a great option if you really want to eat somewhere that you will feel awkward doing so alone.
I hope you do it. It's such an amazing way to take in Disney.