As for when you can sign up for the National rally in Goshen, Indiana, that happens in the spring. Watch this forum for posts regarding the rally. There will be a post to sign up, and then further posts regarding volunteers needed for various things. Different things get posted from the spring until the rally.
There are some things you have to sign up for ahead, like the Amish dinner, the wash and wax, the ladies driving school, etc. Those things are first come, first served, and you easily miss out by not being on top of things.
2017 High Country 305RL
2015 Ford F-250 Super Duty