The information you've already received is good. I want to add that it's crucial for you to keep an eye on their websites. I've had a few conversations with people all excited and set to run the very next upcoming Disney race until they discover that it sold out months ago and quite often within hours of actually going on sale.
<Poster child raises hand>
For this year, I was all excited about MW until I realized that I had missed, or never set, my registration reminders.
If you haven't already, go ahead and create a rD account so you are in the system.
The next step is to install the Telegram app and subscribe to the "runDisney Alerts" thread which tells you when race registration is open. After the initial registration is closed, you will see alerts throughout the following months where registration opens and closes, usually within seconds, even though to my surprise, the MW registrations stayed open for nearly an hour, which is how I got into Goofy for 2024.
The key is to keep the Telegram app up and running and be ready to jump when you see the registration open. The caveat is that you will get alerts for
every rD race, so be prepared for your computer/phone/watch to be buzzing a lot for races you may not be interested in running. (As soon as I finished registering, I turned off notifications in the app, just to not having them setting off my devices and being a distraction all the time).
The other lesson learned is that while you may have received the "registration closed" notification while in the middle of registering, if you started the registration process, keep clicking on submit. We had one member here who kept doing that and eventually it took. <Kicks self for not being more persistent on earlier tries>.
The other lesson is to have your address, credit card number, etc up in notepad so that you can cut-n-paste it. Also know your anticipated finish time, t-shirt size, whether you are staying on property, are you part of a particular run group (like active military) etc so that you can get through the registration page as quickly as possible.
The last method is the run charities. If you go that route, be prepared to raise a bunch of money, or simply pay a large donation for a number. Sometimes, as race day nears, these charities will try to sell numbers of people who backed out or didn't raise any money.
But by far the easiest method is to have the reminders set and your calendar clear so that you can start registering as soon as registration opens.
YMMV