Firstly, head into your hub page in mypthub.
Then you can start creating your workouts that you would like to use inside the challenge you are hosting.
Once you have created the amount of workouts required, you can head into your programs area and create a program, call it your challenge name and then add the workouts into each day in the schedule for your clients.
Once you have completed the program, you are then able to add this into a package under the assignments section as pictured below -
I would suggest setting this program to start on the same date within the package for all clients and ensuring they can all get signed up before this date.
Creating a group chat is also an awesome way to keep clients communicating with each other and to give them that community feel when completing a challenge.
You can do this in your 'chat' tab > create a chat and select the group option. You can then add clients into these and they can communicate with each other!
You can even create a discount voucher to market the challenge on your social media!
The discount just needs to be copied so that your clients can copy this when checking out and purchasing the package.