As I said the Wave is always 'get your pass the day of the hike'. However you can assume that the cold weather months draw many fewer people to the auction so you will most likely get a permit. In the summer the odds are against you.
The Wave hike is well represented on YouTube, watch some of those. It is not a hike for newbies as there is no trail just rock cairns on a red rock trail. You can get lost, people get stranded over night. So be prepared.
Getting the PermitThe hikeParia CanyonI don't know if you are experienced hiking out in red rock country but bring 3 times as much water as you think you'll need.