How the practice run will work: (post edited at 1:53 - 2:00 PM PST at April 4th)
All participants must post a screenshot on the beginnning of level 1-1 once the clock hits the time of the live run. Since the event is at 7:30 PM ET, do not post a miiverse screenshot before that time. Posting it after 7:30 PM ET is okay. Better late than never in this case! Doing this prevents people from starting too early and gaining an upper hand.
The screenshot should be done after the intro scene of level 1-1. It should also show your character with no power ups or items reserved. Here's how the picture should look.

Afterwards, we will play according to the rules I post in the thread.
Those rules would be the second and third post from this thread which you can find here by clicking here and here but below is quick summary of how to play:
1. Start the world 1-1 with no power ups or items reserved.
2. Tap the green miiverse post at the end of the level to make a miiverse post that tags the name of the level you've completed.
Remember that posting this way bypasses miiverse' two minute limit for successive posts. So don't worry about finishing the level under a minute after the first miiverse screen shot post!
3. Give each other the link to our Miiverse user page so we can check the activities page. There, we can find all the levels we completed.
(optional)
I will bump this thread half an hour or an hour before the event begins. Feel free to post in this thread to reconfirm you're playing or that you are setting up the game and simply waiting to post a screen shot at 7:30 PM ET. You can also tell people how excited you are to be the first people to test this concept 
Remember we are only playing World 1 and 2. The shortcut to get to World is 2 is not allowed. What levels you can play can be found in the following green link: what levels are we playing ?
And I think that's about it! Let me know if you need any more details clarified or more rules should be established.